What is the ruling regarding my previous prayers in which I did not move my tongue and lips during recitation, and how many prayers must I repeat? Is expiation obligatory if I am not sure about having sworn an oath on something?

We have previously emphasized the obligation to move the lips and tongue during recitation. Whoever was unaware of this must, according to the majority of scholars, repeat the missed prayers. He should do so to the best of his ability. If he is unsure of their number, he should estimate until he is reasonably certain that he has fulfilled his obligation. Sheikh al-Islam Ibn Taymiyyah, however, holds that repetition is not obligatory for someone whose prayer was invalidated due to ignorance or a faulty interpretation. As for doubt regarding an oath, it does not necessitate expiation.