As-Salamu alaikum brothers and sisters, I want to know what happens if a person has been doing a mistake that invalidates his salah, and dies before realising it? Also, the saying is if somebody is unsure whether he lost his wudu, he should look for a sound or a smell, what if he lost his wudu but assumed he didn't because he didn't smell or hear anything?
If someone makes a mistake in pray er or in wudu, and they were not aware of that, they are excused for their ignorance on the matter. If they did not realise their errors, they are not taken to account for that.
And Allah, may He be exalted, says (interpretation of the meaning): “And there is no sin on you if you make a mistake therein, except in regard to what your hearts deliberately intend. And Allah is Ever Oft-Forgiving, Most Merciful” [al-Ahzaab 33:5].
And the Prophet (blessings and peace of Allah be upon him) said: “Allah has forgiven my ummah their mistakes and forgetfulness, and what they are forced to do.”