Cleaning the mosque
Question

                Please could you tell me what reward would one get by regulating to the mosque also cleaning it .
Praise be to Allah.
    There is no report of any specific virtue attached to 
    cleaning the mosque, except that the Prophet  (peace and blessings of 
    Allaah be upon him) commanded that the mosque should be cleaned and 
    perfumed. It was narrated that Samurah ibn Jundub said: “The Messenger of 
    Allaah  (peace and blessings of Allaah be upon him) commanded us to set 
    up mosques among our houses and commanded us to clean them.” (Narrated by 
    Ahmad in his Musnad, 19671; classed as saheeh by al-Albaani in 
    Saheeh al-Targheeb wa’l-Tarheeb, 278). 

    And it was narrated that ‘Aa’ishah said: “The Messenger of 
    Allaah  (peace and blessings of Allaah be upon him) commanded that 
    mosques should be built among the houses (i.e., in each neighbourhood), and 
    that they should be cleaned and perfumed.” (narrated by al-Tirmidhi, 594; 
    classed as saheeh by al-Albaani in Saheeh al-Targheeb wa’l-Tarheeb, 
    279). 
These two ahaadeeth refer 
    to the command of the Prophet  (peace and blessings of Allaah be upon 
    him), and the one who obeys the command of the Prophet  (peace and 
    blessings of Allaah be upon him) will be rewarded. 

    It was narrated from Abu Hurayrah that a black man (or a 
    black woman) used to clean the mosque, and he died. The Prophet  (peace 
    and blessings of Allaah be upon him) asked about him, and they said that he 
    had died. He said, “Why did you not tell me? Show me his grave.” (Or he 
    said, “her grave.”) So he went to her grave and offered the funeral prayer 
    for her. (Narrated by al-Bukhaari, 458; Muslim, 956). 

    Ibn Hajar said in Fath al-Baari, “The hadeeth 
    indicates the virtue of cleaning the mosque, enquiring after servants and 
    after friends if they are absent.” 

    Moreover, for the Muslim to do an act of worship or obedience 
    it is sufficient for him to know that this is the command of Allaah and His 
    Messenger. This is a sign of complete submission to the teachings of Islam, 
    but there is nothing wrong with asking about the reason behind it or the 
    reward for it, in order to feel more content with doing it. 

    Note: there is a da’eef (weak) hadeeth about the virtue of 
    cleaning the mosque, which says, “Sweeping the mosque is the dowry of al-hoor 
    al-‘iyn.” (al-Silsilah al-Da’eefah, 4147), The saheeh reports 
    narrated above are sufficient. And Allaah knows best.