‘Ali said that the Prophet used to say at the end of his witr, “O God, I seek refuge in Thy good pleasure from Thine anger, and in Thy forgiveness from Thy punishment, and I seek refuge in Thy mercy from Thy wrath.* I cannot reckon the praise due to Thee. Thou art as Thou hast glorified Thyself.”
* Literally ‘in Thee from Thee’.
Abu Dawud, Tirmidhi, Nasa’i, and Ibn Majah transmitted it.