Tafseer of the verse “We will show them Our Signs in the universe, and in their own selves, until it becomes manifest to them that this (the Quran) is the truth” [Fussilat 41:53]
Question

                What is the tafseer of the second to the last aya of surat Fussilat which talks about Allah showing his signs to the disbelievers. Does this aya mean that they would realise Islam before their death and hence, the is no respite for any disbeliever on the day of Judgement. And also, the authenticity of the hadeeth reported by Ahmad in Musnad that the ones who didnt hear the message of Islam would be tested.
Praise be to Allah.
    Allah, may He be glorified and exalted, says (interpretation of the 
    meaning):

    “We will show them Our Signs in the universe, and in their 
    own selves, until it becomes manifest to them that this (the Quran) is the 
    truth” 

    [Fussilat 41:53]. 

    What the verse means is that this is a promise from Allah, may He be 
    exalted, that He will show people His signs in different regions of the 
    heavens and the earth and in their own selves so that it may become clear to 
    them and they may understand that the Qur’an is the truth sent down by 
    Allah. 

    The mufassireen (commentators) differed concerning the meaning of “the 
    universe” in this verse , but the differences of opinion do not affect the 
    meaning; rather the verse may be understood in all the ways that they 
    suggested, so there is no contradiction between them. 

    Some of the commentators interpreted the word translated here as universe as 
    referring to different regions of the heavens, some interpreted it as 
    referring to different regions of the earth, and some interpreted it as 
    referring to both, as referring to different regions of both the heavens and 
    the earth. 

    With regard to the phrase “and in their own selves”, some of them 
    interpreted it as being addressed to the people of Makkah who did not 
    believe in the Prophet (blessings and peace of Allah be upon him), and 
    understood it as referring to the day of Badr and the conquest of Makkah; 
    that was a sign from Allah, may He be exalted, that He was supporting His 
    Prophet and would grant him victory against his enemies despite the small 
    number of his Companions and their lack of resources, which was a sign that 
    he was truly the Messenger of Allah and that what he brought was truly from 
    Allah. Others interpreted it as referring to man’s own self in general 
    terms, and the perfection of his physical makeup and the brilliance of 
    Allah’s design in the creation of man, which points to His oneness and the 
    perfection of His might, knowledge and wisdom and so on. The verse may be 
    understood as referring to both meanings, as there is no contradiction 
    between them. 

    Allah, may He be exalted, indeed fulfilled His promise and showed people His 
    signs in the universe and in their own selves throughout the fourteen 
    centuries that followed this promise, from which it is clear to any 
    reasonable and fair-minded individual that Islam is the truth and the Qur’an 
    is true. 

    Allah, may He be exalted, is still disclosing to people new signs all the 
    time, and these signs will continue to appear until the world ends. For 
    Islam came for all of mankind until the Hour begins, so it is appropriate 
    that His signs and miracles should abide until the onset of the Hour. 

    There follow the views of some of the commentators on this verse. 

    Al-Qurtubi (may Allah have mercy on him) said: 

    The words “We will show them Our Signs” mean: indicators of Our 
    Oneness and might
“in 
    the universe [different regions of the earth]” that is, the ruins of the 
    dwellings of past nations
“and 
    in their own selves” by means of calamities and sickness. 

    Ibn Zayd said: “in the universe” means the signs of the heavens, “and 
    in their own selves” means events on earth. 

    Mujaahid said: “in the universe [different regions of the earth]” 
    refers to the conquest of cities. Allah, may He be glorified and exalted, 
    enabled His Messenger (blessings and peace of Allah be upon him) and the 
    caliphs after him and the supporters of His Religion to conquer cities 
    throughout the world, east and west, and in the west in particular He 
    enabled them to make conquests the like of which He had not enabled any 
    ruler on earth to make before them, and to overwhelm tyrants and kings, and 
    He caused the small numbers (of the Muslims) to overcome the great numbers 
    (of their enemies), and caused the weak (Muslims) to prevail over the strong 
    (disbelievers). And He caused to happen at their hands remarkable and 
    extraordinary feats.
“and 
    in their own selves” refers to the conquest of Makkah. This is the view 
    favoured by at-Tabari. 

    ‘Ata’ and Ibn Zayd said: “in the universe” means the different 
    phenomena in the heavens and the earth, such as the sun, moon, stars, night, 
    day, wind, rain, thunder, lightning, storms, plants, trees, mountains, 
    oceans, and so on…
“and 
    in their own selves” refers to the precise nature of man’s creation and 
    the brilliant wisdom in everything than Allah designed in man, even the way 
    of defecation and urination, for food and drink enter one place, then 
    separation occurs and they come out from two places. And we see the precise 
    creation and wisdom of Allah in the eyes, which are like two drops of water, 
    through which he sees the distance between heaven and earth, which is the 
    distance of five hundred years; and in the ears which can distinguish 
    between various sounds, and other examples of the precise and brilliant 
    creation of Allah. 
“until 
    it becomes manifest to them that this (the Qur’an) is the truth”. There 
    are four opinions as to what is referred to by “this”:

    1.that it is the 
    Qur’an

    2.that it is Islam, 
    which the Messenger brought to them and called them to

    3.that what Allah 
    shows them and does of that is the truth

    4.that Muhammad 
    (blessings and peace of Allah be upon him) is the true Messenger.

    End quote from Tafseer al-Qurtubi (15/374-375) 

    These four interpretations are all true, and are all interconnected. But the 
    apparent meaning is that what the verse refers to is the Holy Qur’an. This 
    is what is indicated in the preceding verse (interpretation of the meaning):
    

    “Say: "Tell me, if it (the Quran) is from Allah, and you 
    disbelieve in it, who is more astray than one who is in opposition far away 
    (from Allah’s Right Path and His obedience)” 

    [Fussilat 41:53].
    

    Madaarij as-Saalikeen 
    by Ibn al-Qayyim (3/466). 

    Ibn Katheer (may Allah have mercy on him) said:

    That is, We will show them Our evidence and proof that the Qur’an is true 
    and has indeed been sent down from Allah, may He be glorified and exalted, 
    to His Messenger (blessings and peace of Allah be upon him), on the basis of 
    external signs “in the universe”, such as the conquests and 
    prevalence of Islam in various regions and over all other religions. 

    Mujaahid, al-Hasan and as-Saddi said: The signs in their own selves include 
    the battle of Badr, the conquest of Makkah, and similar events that happened 
    to them, in which Allah granted victory to Muhammad and his companions, and 
    inflicted a humiliating defeat on falsehood and its followers.

     It may also be that what is meant here is man and his physical composition, 
    as is explained in the science of anatomy, which points to the wisdom of the 
    Creator, may He be blessed and exalted, and the different inclinations and 
    opposite natures that people have, good and bad and in between, and the 
    divine decrees to which man is subjected, which he cannot escape and over 
    which he has no control.

    End quote from Tafseer Ibn Katheer (7/187) 

    Some commentators combined all that has been said regarding the meaning of 
    this verse, because there is no contradiction between any of it, as stated 
    above. 

    As-Sa‘di (may Allah have mercy on him) said: 
If 
    you – O disbelievers – doubt that the Qur’an is sound and true, then Allah 
    will establish proof for you and will show you His signs in the universe, 
    such as the signs in the heavens and the earth, and what Allah may He be 
    exalted, tells us about of momentous events that point to the truth, for the 
    one who has eyes to see. 
“and 
    in their own selves” such as what their own bodies contain of wondrous 
    signs of Allah and of the amazing precision of His creation and the 
    greatness of His might, and the punishments and calamities that He sent upon 
    the disbelievers, and the support He granted to the believers.
“until 
    it becomes manifest to them” that is, until it becomes clear to them, 
    from these signs, beyond any shadow of a doubt
“that 
    this (the Quran) is the truth” and what it contains is truth. 

    And Allah, may He be exalted, indeed did that: He showed His slaves signs 
    through which it became quite clear to them that it is the truth, but Allah 
    is the One Who enables whomever He will to believe, and He leaves astray 
    whomever He will. End quote. 

    Tafseer as-Sa‘di 
    (p. 752) 

    Muhammad al-Ameen ash-Shinqeeti said in 
    Adwa’ al-Bayaan 
    (7/67-68): 

    Allah says (interpretation of the meaning): “It is He, Who shows you His 
    Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.)” [Ghaafir 
    40:13]. What Allah, may He be glorified and exalted, says in this verse 
    is that He is the One Who shows His creation His signs, and He explains that 
    and clarifies further elsewhere; He states that He will show them His signs 
    in the universe and in their own selves, and the purpose behind that 
    explanation is to highlight to them that what Muhammad (blessings and peace 
    of Allah be upon him) brought is truth, as Allah, may He be exalted, says 
    (interpretation of the meaning):

    “We will show them Our Signs in the universe, and in their 
    own selves, until it becomes manifest to them that this (the Quran) is the 
    truth” 

    [Fussilat 41:53]. 

    Allah, may He be glorified and exalted, has highlighted the wonders of His 
    creation in the different regions of the heavens and the earth, which 
    indicate to every wise person that He is the Lord Who alone is deserving of 
    worship. These wonders include the sun, moon, stars, trees, mountains, 
    animals, oceans, and so on. 
He 
    also explains that another of His signs which He shows them and of which 
    they cannot deny anything, is the fact that He has subjugated livestock 
    animals to them so that they may ride them, eat of their flesh, and make use 
    of their milk to make butter, ghee and yoghurt, and make clothes from their 
    skins, wool and hair, as He, may He be exalted, says (interpretation of the 
    meaning):

    “Allah, it is He Who has made livestock animals for you, that 
    you may ride on some of them and of some you eat.

    And you have (many other) benefits from them, and that you 
    may reach by their means a desire that is in your breasts (i.e. carry your 
    goods, loads, etc.), and on them and on ships you are carried”

    [Ghaafir 40:79-80]. 

    Among other signs that He shows to some of His creation are the miracles of 
    His Messengers, for miracles are signs that highlight the truthfulness of 
    the Messengers, as Allah, may He be exalted, says concerning Pharaoh 
    (interpretation of the meaning):

    “And indeed We showed him (Fir‘awn (Pharaoh)) all Our Signs 
    and Evidences, but he denied and refused”

    [Ta-Ha 20:56]. 
In 
    another verse, Allah states that among the signs He shows to His creation is 
    His punishment of those who disbelieve in the Messengers, as He, may He be 
    exalted, said in the story of the destruction of the people of Loot 
    (interpretation of the meaning):

    “And indeed We have left thereof an evident Ayah (a lesson 
    and a warning and a sign the place where the Dead Sea is now in Palestine) 
    for a folk who understand”

    [al-‘Ankaboot 29:35]. 

    And He said concerning His punishment of Pharaoh and his people with the 
    flood, locusts and lice, etc. (interpretation of the meaning):

    “So We sent on them: the flood, the locusts, the lice, the 
    frogs, and the blood: (as a succession of) manifest signs”

    [al-A‘raaf 7:133].

    End quote. 

    Despite the clarity of the signs, many people do not use their reason, 
    vision and hearing to reflect on these signs in order to arrive at the 
    truth. Thus they are as Allah describes them (interpretation of the 
    meaning):

    “They have hearts wherewith they understand not, they have 
    eyes wherewith they see not, and they have ears wherewith they hear not (the 
    truth). They are like cattle, nay even more astray; those! They are the 
    heedless ones”

    [al-A‘raaf 7:179]. 

    The truth is apparent to many people, but they stubbornly deny it, either 
    out of envy or out of fear for their worldly status, or for other reasons. 
    Similarly, the leaders of the disbelievers in Makkah, such as Abu Jahl and 
    others, acknowledged the truthfulness and Prophethood of the Prophet 
    (blessings and peace of Allah be upon him), but they presented the opposite 
    of that in their words. Allah, may He be exalted, said concerning them 
    (interpretation of the meaning):

    “it is not you that they deny, but it is the Verses (the 
    Quran) of Allah that the Zalimoon (polytheists and wrongdoers) deny”

    [al-An‘aam 6:33]. 

    Despite the fact that these signs are so clear, there are some among the 
    disbelievers whom the call of Islam has not reached, or they are excused, 
    such as the insane or those who died in childhood before reaching the age of 
    understanding and accountability. These are the ones who the hadiths say 
    will be tested on the Day of Resurrection. 
It 
    was narrated by Imam Ahmad (16301), Ibn Hibbaan (7357) and at-Tabaraani in
    al-Kabeer (841) from al-Aswad ibn Saree‘ that the Prophet of Allah 
    (peace and blessings of Allah be upon him) said: “There are four (who will 
    make their excuses to Allah) on the Day of Resurrection: a deaf man who 
    never heard anything, an insane man, a very old man, and a man who died 
    during an interval between the sending of two Messengers. The deaf man will 
    say, ‘O Lord, Islam came but I never heard anything.’ The insane man will 
    say, ‘O Lord, Islam came but the children ran after me and threw dung at 
    me.’ The very old man will say, ‘O Lord, Islam came but I did not understand 
    anything.’ The man who died during the interval between the sending of two 
    Prophets will say, ‘O Lord, no Messenger from You came to me.’ He will 
    accept their pledges to obey Him, then He will send word to them to enter 
    the Fire. By the One in Whose hand is the soul of Muhammad, if they enter 
    it, it will be cool and safe for them.”

    Classed as saheeh by al-Bayhaqi in al-I‘tiqaad (p. 169) and by al-Albaani 
    in as-Saheehah (1434). Al-Haythami said in al-Majma‘ (7/216): 
    Its men are the men of as-Saheeh 

    For more information, please see also question no. 98714

    And Allah knows best.