He was junub and the iqaamah for prayer was given – should he pray or do ghusl even if he will miss the prayer in congregation?
Question

                If a man is junub and the time for prayer comes, should he go and pray in the mosque or must he do ghusl first and then pray after that?.
Praise be to Allah.
    The person who is junub must do ghusl in order to pray, and 
    his prayer is not valid without it, because Allaah says (interpretation of 
    the meaning): 

    “O you who believe! Approach not As‑Salaah (the prayer) 
    when you are in a drunken state until you know (the meaning) of what you 
    utter, nor when you are in a state of Janaaba (i.e. in a state of sexual 
    impurity and have not yet taken a bath), except when travelling on the road 
    (without enough water, or just passing through a mosque), till you wash your 
    whole body”

    [al-Nisa’ 4:43].

    And the Prophet  (peace and blessings of Allaah be upon 
    him) said: “No prayer is accepted without purification.” Narrated by Muslim 
    (224). 

    This is a matter upon which there is scholarly consensus. 

    Al-Nawawi (may Allaah have mercy on him) said: The Muslims 
    are unanimously agreed that prayer is haraam for the one who is impure, and 
    they are unanimously agreed that prayer is not valid if he does it, whether 
    he knows that he is impure or he was unaware of it or forgot it. But if he 
    prays out of ignorance or because he forgot, there is no sin on him. If he 
    knew of the impurity and the prohibition on praying when impure, then he 
    committed a grave sin, but in our view he does not commit kufr thereby 
    unless he regarded that as permissible. But Abu Haneefah said: He does 
    commit kufr because he took the matter lightly. 

    Conclusion: it is a sin, do it is like zina and other sins. 
    That is if he was forced to pray when impure. End quote from al-Majmoo’ 
    (2/78). 

    The one who is junub must do ghusl first, then pray, even if 
    doing ghusl means that he will miss the prayer in congregation. 

    See also question no. 94311. 

    And Allaah knows best.