Is there any verse in the Quraan or the Hadith which indicates that it is permissible in certain circumstances to Qadha Salaah?
According to a tradition recorded in Saheeh Al-Bukhaari, it is narrated that the Prophet (S.A) said, “Whoever sleeps away from a Salaat or he forgets it let him perform it when he remembers (about it).”
This tradition makes it very clear that whenever a person leaves off a salaat, then as soon as he remembers, he must perform it.
As for the Holy Quraan, it has mandated us to perform Salaat on its time and has made it clear that it is a duty upon us to fulfill as a command from Allah. It therefore means that as long as we do not perform the Salaat, we would not be fulfilling this duty which we owe to Allah.
There are also traditions recorded in Saheeh Al-Bukhaari and other books, which show that in certain cases, the Prophet (S.A) and his blessed companions performed Qadha salaah.
It is thus an established teaching in Islam that if one cannot perform Salaat on time (due to a valid reason), then that salaah must be performed as Qadha at the earliest given opportunity.
And Allah knows best.
Mufti Waseem Khan