Fiqh-us-Sunnah Volume 002, Supererogatory Prayer, Fiqh 2.044.

Section : Supplications during the prostration.

Whoever makes this prostration may supplicate whatever he wishes. There is nothing authentic from the Prophet sallallahu alehi wasallam on this point except for the hadith from 'Aishah who said: "When the Prophet made the sajdah of the Qur'anic recital, he would say: 'I have prostrated my face to the One Who created it and brought forth its hearing and seeing by His might and power. Blessed be Allah, the best of Creators.'" This is related by the five, except Ibn Majah, and al-Hakim. At-Tirmizhi and Ibn as-Sakan grade it sahih. The later however adds that at the end the Prophet would say, three times, what he always said in his sujjud: "Glory be to my Lord, the Most High," that is, if he was making the sujjud of recital during a prayer.