The two prostrations of forgetfulness rebuke the shaytan

Malik relates from Zayd ibn Aslam from Ata ibn Yasar mursal: if one of you doubts his prayer and does not know whether he prayed three or four, let him pray one rak a and prostrate twice sitting before the salam; if the rak a was the fifth the two prostrations complete it, and if it was the fourth the two prostrations are a rebuke to the shaytan ¹ Muwatta 252.

In this report the two prostrations of forgetfulness, when the prayer is complete, are a rebuke to the shaytan — a rebuff to him for what he whispered into the worshipper s prayer ¹.

From the prayer fiqh of the Muwatta; the Jinn & Devils Browser shows it in the devils section ¹.