Do prayers that were performed while part of the leg, hand, or foot was uncovered, or that were performed with an insufficient covering, such as a blanket, need to be re-performed, knowing that the questioner was unaware that the prayer was invalid due to that?

Some jurists, including Sheikh al-Islam Ibn Taymiyyah, have held the view that whoever commits an act that invalidates prayer, or omits a pillar or condition out of ignorance, is not required to repeat the prayer. They cite as evidence the Prophet's (peace be upon him) not commanding some of his Companions to repeat their prayers after their error became clear to them. Furthermore, the unintentional uncovering of a small portion of the 'awrah (private parts) does not invalidate the prayer according to many scholars. However, if the uncovering was intentional, it invalidates the prayer according to the majority.