And the evidence that the Prophet, peace and blessings be upon him, only commanded the one who is doubtful in his prayer to perform the two prostrations of forgetfulness after he builds upon the lesser (number), so he completes his prayer based on certainty if he does not have any inclination.

Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When any of you has doubt in his prayer, he should leave the doubt and act upon what is certain. Then, if he becomes certain that his prayer is complete, he should perform two (prostrations of forgetfulness) sajdahs. If his prayer was complete, then that rak'ah and the two sajdahs will be counted as voluntary (nafl) acts, and if the prayer was not complete, then this rak'ah will complete his prayer and the two sajdahs will be a means of humiliating and disgracing Satan."