Question: What is the ruling on delaying prayer due to work?
Answer: “If delaying the prayer is from the beginning of the time until it’s end only; however, he prays in its time, then there is nothing upon him. This is because preceding the prayer to the beginning time is by way of excellence, not obligation. This is if there is no congregation in the masjid. Otherwise, it is obligatory to be present for the congregation, except if he has a need to leave it off.
As for delaying the prayer after its time exits, then this is not allowed. Except if a person forgets or is overcome by work that it distracts from the prayer. The Prophet (ﷺ) said:
من نام عن صلاة أو نسيها فليصلها إذا ذكرها
If any one of you forgets a prayer or sleeps and misses it, let him pray it when he remembers it.’
So this one, when he remembers it he prays it. There is no blame on him. As for if he remembers; however, due to the busyness he is involved in he delays it [after its time] then this is unlawful. If he prays it after the time in this condition, then it is not accepted due to the statement of the Prophet (ﷺ):
من عمل عملاً ليس عليه أمرنا فهو رد
He who innovates something in this matter of ours (i.e., Islam) that is not of it will have it rejected (by Allah).
Shaikhul Islaam Ibn Taymiyyah rahimahullah mentioned whoever delays the prayer from its time without a legislated excuse, then there is no prayer for him because he removed it from the time which it he was ordered to fulfill it in without a need. So he has come with an action which is not from the affair of Allah and His Messenger. And is the Muwaffaq”.
[Majmoo’ al-Fatwa wa Rasail (12/32)]
Faisal Ibn Abdul Qaadir Ibn Hassan