Sunan al-Nasa'i — The Book of Forgetfulness (In Prayer)

“The Prophet(ﷺ) prayed Zuhr with five rak’ahs, and it was said to him: ‘Has something been added to the prayer?’ He said: ‘Why are you asking?’ They said: ‘You prayed five.’ So he turned around and prostrated twice.”

The Prophet (ﷺ) said: If anyone says in the morning or in the evening: “O Allah! in the morning we call Thee, the bearers of Thy Throne, Thy angels and all Thy creatures to witness that thou art Allah (God) than Whom alone there is no god, and that Muhammad is Thy Servant and Apostle,” Allah will emancipate his fourth from Hell; if anyone says twice, Allah will emancipate his half; if anyone says it thrice, Allah will emancipate three-fourth; and if he says four times, Allah will emancipate him from Hell.

“I asked Abu Ja’far: Was it narrated to you from Jabir bin ‘Abdullah that the Prophet performed ablution washing each part once?’ He said: ‘Yes.’ I said: ‘And each part twice, and each part thrice?’ He said: ‘Yes.'”