Alhamdulillah Iv been taking the online tests but there is one question that confused me:
Which of the following sins will Allaah not forgive (unless the sinner repents sincerely)?
(Choose all answers that are correct.)
3.burying one's daughter alive
At first look the answer was obvious- shirk, Allaah does not fogive that partners be set up in worship but He forgives all else that He pleases.
BUT- as the question had in parenthesis (unless the sinner repents sincerely)
-someone can sincerly repent from comitting shirk with Allaah before they die.
As for suicide, although a person is dead and cannot make tawbah he is left under the Will of Allaah, if He wills He will Punish, if He wills, He will Forgive.
wa alaykumus-salāmu wa rahmatullaahi wa barakaatuh...
What you have understood about the Muslim who commits suicide is correct, and it is the belief of Ahl al-Sunnah.
To be technical on the issue of someone committing suicide, we could understand that suicide could be done instantly or not.
Meaning, some people commit suicide by shooting themselves in the head, or jumping off a building. No real chance of repentance there.
However, some people commit suicide in a slower manner, like by poisoning themselves, or slitting their wrists, etc. These ways include the person living for a time after committing the action that takes their lives. So a person who is dying from some lethal action they have taken against themselves may possibly reflect, have remorse, and repent from the sin.
While the base ruling on repentance is that it is not accepted at the time of impending death, we hope for Allaah's forgiveness for them, and Allaah knows best about each and every case. The Prophet (ṣallallāhu alayhe wa sallam) used to continue inviting people to Islām on their death beds as they were dying (his uncle, the Jewish boy, etc.).