Mistake in Sujud (prostrations)

“Abu ’Abd Allah (a.s.), was asked about a man who becomes confused and does not know if he has done one or two Sajdah (prostrations). He (the Imam) said, ’He performs another Sajdah (prostration) and after completion of Salah (prayer) two Sajdah (prostration) because of mistake is not necessary.’”

“I once asked abu ’Abd Allah (a.s.), about a man who doubts and does not know if he has performed one or two Sajdah (prostrations). He (the Imam) said, ‘He performs Sajdah (prostration) to ascertain that it is two Sajdah (prostrations).”’

“I once asked abu al-Hassan (a.s.), about a man who performs one Rak’at of Salah (prayer), then he remembers in the second Rak’at in Ruku’ (bowing down on one’s knees) position that he has omitted one Sajdah (prostration) of the first Rak’at. He said, ‘Abu al-Hassan (a.s.), would say that if you omit Sajdah (prostration) in the first Rak’at and do not know if it is one or two; perform Salah (prayer) again until it is correct to say that two Sajdah (prostrations) are performed.’”

“About a man who doubts and does not know if he has performed one or two Sajdah (prostrations), abu ‘Abd Allah (a.s.), has said, ‘He performs one more Sajdah (prostration).”’