Du’a for Marketplace: Authentic?
Question

Is the dhikr for entering the marketplace to be recited when entering supermarkets, grocery stores or specialty stores?
Praise be to Allah.Hadith about du’a for entering the marketplace 
The hadith about the du’a for entering the marketplace is mentioned in the hadith in which the Prophet (blessings and peace of Allah be upon him) said: “Whoever enters the marketplace and says ‘La ilaha ill-Allahu wahdahu la sharika lahu, lahu’l-mulku wa lahu’l-hamdu, yuhyi wa yumit wa huwa hayyun la yamut, bi yadihi’l-khayr, wa huwa ‘ala kulli shay’in qadir (There is no god but Allah Alone, with no partner or associate; to Him belongs sovereignty and to Him be all praise; He grants life and causes death, and He is ever-living and will never die; in His Hand is all goodness and He has power over all things),’ Allah will record for him one thousand thousand good deeds, and will erase from his record one thousand thousand bad deeds, and will raise him one thousand thousand degrees.”. (Narrated by at-Tirmidhi in as-Sunan, 3428)
Status of hadith about du’a for entering the marketplace
The scholars differed concerning the status of this hadith, and there are three views:

The first view is that it is extremely da‘if (weak) and munkar (odd).

Abu Hatim (may Allah have mercy on him) said: “This hadith is munkar jiddan (very odd), and it is not possible that Salim narrated this hadith.” (Al-‘Ilal, 5/312)
‘Ali ibn al-Madini (may Allah have mercy on him) said:
“This hadith is munkar (odd). It is one of the hadiths narrated by Muhajir, claiming that he heard Salim, but in fact this hadith was narrated by a shaykh who is not proven to be a good narrator; his name was ‘Amr ibn Dinar Qahraman Al az-Zubayr, narrated to us from him by Ziyad ibn ar-Rabi‘. Our companions regarded this hadith as extremely odd, even though its isnad appears to be good. If the hadith narrated by Muhajir about [the du’afor entering] the marketplace was sahih, there would be no criticism of ‘Amr ibn Dinar concerning this hadith.” (Musnad al-Fariq (2/641) by al-Hafiz Ibn Kathir)
Al-Bukhari deemed one of the isnads of this hadith to be munkar (odd), as noted in al-‘Ilal al-Kabir by at-Tirmidhi (no. 363).
Al-Mulla ‘Ali al-Qari (may Allah have mercy on him) said:
“It was said that it has no basis, or that it is fabricated.” (Al-Asrar al-Marfu‘ah, 329)
Shaykh Ibn Baz (may Allah have mercy on him) said:
“What supports the view that it is da‘if (weak) is the strangeness and oddness of its matn (text) because one of the principles of the leading scholars of hadith is that mention of an immense reward for a small deed is an indication that the hadith is da‘if. Undoubtedly what is mentioned in the text is very strange, in terms of the number of hasanat (rewards for good deeds) to be given, the number of bad deeds to be erased, and the number of degrees to be raised.
But the fact that this text is regarded as weak and odd does not mean that it is not prescribed to recite dhikr when entering the marketplace, because it is a place of heedlessness and distraction from remembrance of Allah, so reciting dhikr in that place is an act of great virtue, which may prompt the heedless to follow the example of the one who is reciting dhikr so that they too will remember Allah. And Allah is the source of strength.” (Majmu‘ Fatawa Ibn Baz, 26/248)

The second view is that it is mildly da‘if (weak).

Imam at-Tirmidhi (may Allah have mercy on him) described it as gharib (strange), as noted in as-Sunan (3428).
Al-‘Aqili (may Allah have mercy on him) said:
“Its isnads are layyin (somewhat unreliable).” (Ad-Du‘afa al-Kabir, 3/304)
Ad-Daraqutni (may Allah have mercy on him) said:
“The hadith goes back to ‘Amr ibn Dinar, whose hadith is da‘if (weak), and cannot be quoted as evidence.” (Al-‘Ilal, (2/50)
Ibn al-‘Arabi al-Maliki (may Allah have mercy on him) said: (It is not sahih.” (‘Aridat al-Ahwadhi, 7/32)
Ibn al-Qayyim (may Allah have mercy on him) said: “It is ma'lul (problematic) and such reports cannot be proven.” (Tahdhib as-Sunan, 13/420); al-Manar al-Munif, 33)
Ibn Rajab (may Allah have mercy on him) said: “There is some weakness in its isnad.” (Jami‘ al-‘Ulum wa’l-Hikam, 2/315)
Ibn Hajar said: “Its isnad is somewhat unreliable.” (Fath al-Bari, 11/206)
Al-‘Ajluni (may Allah have mercy on him) said: “There is some weakness in its isnad.” (Kashf al-Khafa, 2/324)

The third view is that the hadith is hasan and is deemed to be acceptable.

Imam al-Mundhiri (may Allah have mercy on him) said: “Its isnad is muttasil (connected) and hasan.” (At-Targhib wa’t-Tarhib, 2/337)
It was classed as hasan by ad-Dimyati in al-Matjar ar-Rabih (p. 473).
Adh-Dhahabi (may Allah have mercy on him) said: “Its isnad is salih gharib [sound but somewhat odd].” (Siyar A‘lam an-Nubala, 17/498)
He said in Tarikh al-Islam (29/346): “It is hasan gharib.” Ash-Shawkani (may Allah have mercy on him) said: “At the very least, it is hasan.” (Tuhfat adh-Dhakirin, 298)
It was classed as hasan by Shaykh al-Albani (may Allah have mercy on him) – after an extensive analysis – in Silsilat al-Ahadith as-Sahihah (no. 3139).
Al-Hakim’s view was a little strange, as he said in al-Mustadrak ‘ala as-Sahihayn (1/722): This is a sahih isnad according to the conditions of al-Bukhari and Muslim, although they did not narrate it.
The view concerning this hadith that is most likely to be correct, and Allah knows best, is the view that the hadith is da‘if (weak) and its isnad is flimsy. This is the view of most of the early scholars of hadith, as we quoted above from some of them. Among contemporary scholars, this view is favoured by Shaykh Ibn Baz (may Allah have mercy on him), as noted above, and by Shaykh ‘Abdullah as-Sa‘d, Muhammad ‘Amr ‘Abd al-Latif (may Allah have mercy on him), Abu Ishaq al-Huwayni, and others. This is also the view of the Permanent Committee for Ifta (1/13/14).
Are we rewarded for reciting du’a when entering the marketplace?
If we accept the view that the hadith is hasan, or slightly weak, there is nothing wrong with the Muslim reciting this dhikr, seeking reward with Allah. If the hadith mentioning the reward is proven sound, then praise be to Allah; if it is not, then he will still attain the reward for remembering Allah in general, which is one of the most beloved of deeds to Allah.
Hence the scholars approved of this dhikr in their books. At-Tabarani said in ad-Du’a (p. 251): Chapter on what is to be said when entering marketplaces; and an-Nawawi said in al-Adhkar (p. 303): Chapter on what one should say when entering the marketplace.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
“Chapter:
Ahmad ibn Hanbal said: If a report speaks of halal and haram, we are very strict in examining isnads. If the report speaks of reward and punishment (for particular deeds), we are more lenient with regard to isnads. This was the approach of the scholars with regard to acting upon da‘if hadiths which speak of the virtue of some righteous deeds. … What they meant by that [i.e., being lenient when examining the isnads of hadiths that speak of reward and punishment] was that if the deed itself is proven to be among the deeds that Allah loves or deeds that Allah hates, on the basis of a religious text or scholarly consensus – for example, good deeds such as reciting Quran, reciting tasbih and du’a, giving charity and freeing slaves, showing kindness to people; or bad deeds such as lying and treachery, and the like – if there is a hadith which speaks of the virtue of some recommended deeds and the reward for them, or the reprehensible nature of some deeds and the punishment for them, and mentioned the amount and types of reward and punishment, if there is another hadith concerning that which we do not know to be fabricated, then it is permissible to narrate it and act upon it. In other words, one would hope to attain that reward or one would fear that punishment. This is like a man who knows that engaging in trade will lead to profit, but he heard that it will bring a large profit; if what he heard is true, it will benefit him, and if it is not true, it will not harm him. An example of that is ideas about reward and punishment [for particular deeds] that come from reports from Jewish sources (Israiliyyat), dreams, the words of the salaf and scholars, stories of the scholars, and other things which cannot, on their own, be taken as the basis for a shar‘i ruling or for deciding whether a particular deed is recommended or not, but they may be quoted by way of encouraging and deterring, giving hope of divine mercy or warning of divine wrath.
So with regard to that which is known to be good or bad on the basis of shar‘i evidence, the type of reports mentioned above may be beneficial and will do no harm, regardless of the degree of soundness of the report. But if a report is known to be false and fabricated, it is not permissible to pay any attention to it, because we cannot base anything on lies. But if the report is proven to be sound, then it may be taken as the basis for shar‘i rulings.
However, if the report may or may not be sound, then it may be narrated because there is the possibility that it could be sound, and because no harm will result if it turns out to be false. Ahmad said: if there is a report that speaks of reward and punishment, we are lenient with regard to isnads, which means that we narrate such reports with their isnads, even if the narrators are not so trustworthy that their reports may constitute proof.
As for the one who said that such reports about the virtues of good deeds may be accepted and acted upon if they speak of the rewards of virtuous deeds, such as reciting Quran and dhikr, and avoiding bad deeds:
If a da‘if hadith speaks of the virtue of an act of worship and describes that act in specific terms, such as praying at a particular time, reciting particular verses, or doing the prayer in a particular manner, it is not permissible to accept these reports, because there is no shar‘i evidence to prove that doing it in this particular way is recommended.  In contrast, if it is narrated that “whoever enters the marketplace and says La ilaha ill-Allah will have such and such,” remembering Allah in the marketplace is recommended, because it is remembering Allah among the heedless. As for the specific reward mentioned in the report, it does not matter whether it is proven to be correct or not.” (Majmu‘ al-Fatawa, 18/65-68)
Can we say du’a for the marketplace when entering grocery stores and small markets?
What is understood from the word marketplace (suq) is what people customarily know as a marketplace, which is a place where there are stores and goods for sale, as mentioned in Lisan al-‘Arab (10/167): “Suq: a place where there are stores. Ibn Sidah said: The suq is where transactions are carried out. It is so called because trade goods and items for sale are brought (tusaq) to it.”
It says in al-Mu‘jam al-Wasit (1/464): “The suq (marketplace) is the place to which goods and items are brought to be bought and sold.”
With regard to everything that people call a marketplace, it is recommended to recite this dhikr and du’a, whether they are marketplaces for clothing, food, or cars, or financial markets and the like. This includes large shopping centres which nowadays are called malls.
But it is sufficient, when entering a shopping centre or mall, to remember Allah at the entrance to the building; it is not prescribed to do so when entering every individual shop within the mall. Similarly, if someone goes to an open-air market in a street, for example, he may remember Allah when he begins shopping, and he does not have to repeat the dhikr at every stall he visits.
With regard to individual shops, small grocery stores, pharmacies and the like, which are standalone businesses to which a person goes for a specific need, and not to browse, and it is not a place that he goes to unless he needs something, it does not seem that such places can be called marketplaces. People still customarily differentiate between small grocery stores and larger marketplaces, which may be in the same location every day, or be held on particular days only, as is the case in some countries.
Whatever the case, if a person remembers Allah when entering such places, whether by reciting this particular dhikr or other adhkar, it is a good and righteous deed, and there is nothing wrong with it. In fact, it is prescribed and recommended in general terms, because there are many reports, which reach the level of being mutawatir, that speak of the virtue of dhikr in both general and specific terms.
For more, please see these answers: 4845 , 5113 , 83393 , 121254 .
And Allah knows best.