Regarding the matter of seeking forgiveness (istighfār), it is a good idea for some of us to remind each other of it in general or specifically on Friday nights or Thursday nights before the descending of deeds. As for those who say that this is an innovation (bidʽah), I consider their claim fun or their claim itself is the innovation. I want to emphasize what our honorable scholars have mentioned, that the frequent use of the word “bidʽah” itself is an innovation.
As for the evidence regarding the issue of seeking forgiveness, it can be found in the Ḥadīths of the Prophet (peace be upon him). Seeking forgiveness (istighfār) is praiseworthy and should be done at all times. It is a means of bringing sustenance, lengthening life, and obtaining righteous offspring. Seeking forgiveness is actually a form of repentance to Allah, and Allah Almighty says: “And turn to Allah in repentance, all of you, O believers, that you might succeed.” [Quran 24:31]. This verse contains a collective invitation to repentance.
As for the issue of allocating a specific time, such as a day, hour, or occasion, the general rule here is that any recommended action to be done or left is permissible to be allocated. This is because the specific is still part of the general. As for the specific, it cannot be generalized except with evidence.
For example, if I say, “Everyone who throws down his weapon is safe,” this indicates generality. Then you come and say, “So-and-so said, ‘Everyone who throws down his weapon today is safe.'” You are also truthful because today is part of the general statement and you have specified it for a certain reason, yet it does not contradict the generality. This is similar to seeking forgiveness, which is general as mentioned in the verses and Ḥadīths. When you specify a day for it to increase attention, there is no harm in that because the specified is part of the general. However, there is a condition for that, which is not to attribute any virtue other than that of seeking forgiveness and remembrance of Allah to this specification. In other words, whoever does not remember Allah on the specified day is not deprived from rewards if they remember on another day, unless there is evidence to the contrary.
We do this kind of specification all the time without any specifier except by custom. For example, a sheikh teaches jurisprudence on Tuesdays every week, recitation on a certain day, and interpretation on another day, and he adheres to that. This is permissible even if there is no evidence for the specification, because the action is recommended to be done at any time, and there is a benefit in the specification.
Fatwa by Dr. Khālid Naṣr