The Criterion for Doubt in Prayer

Question:
I say: Honorable Shaykh, may Allah grant you success, what is the criterion for doubt in prayer, so that what results in waswasah (whispers of Satan) is excluded from it?

Answer:
We have clarified it. We said that doubt is hesitation between two matters where one is not more probable than the other; this is doubt. However, if one is more probable than the other, he acts according to the stronger position, the more probable possibility, which is called preponderance of opinion. If one of the two possibilities becomes more probable than the other, he acts according to the stronger position, which is called preponderance of opinion. As for the second side, the weaker position, this is called illusion; they call it illusion. So if one hesitates between two matters, one being the stronger position and the other the weaker position, the stronger position is called opinion, and the weaker position is called weakness and waswasah (whispers of Satan), so a person leaves it. Yes.