Is a pilgrim's Hajj on behalf of his deceased mother valid, given the extreme crowding during the farewell circumambulation (Tawaf al-Wada'), which compelled him to go up to the roof to complete the circumambulation, and he does not know the exact spot where he had stopped downstairs?

It is advisable to stay away from sins due to their ill effects. Among these effects are deprivation of knowledge and sustenance, alienation between the disobedient person and his Lord and people, difficulty in affairs, darkness of the heart, deprivation of obedience, proliferation of sins, weakening of the will to repent, shedding of the sense of abhorrence for sin, and sealing of the heart. As for the acceptance of acts of obedience, that is up to God, and no one can be certain of it. What is required of a Muslim is to increase in righteous deeds that conform to Islamic law. Regarding interrupting the circumambulation (Tawaf) to complete it on an upper floor, there is no harm in that. The circumambulation is resumed from the point where it was interrupted, and one acts on the prevailing assumption when certainty is unattainable.