What the Messenger used to say when sitting between the two Sujuds

Q 3: It was reported that the Prophet (peace be upon him) used to prolong his Tahajjud (optional late night Prayer), including sitting between the two Sujuds (prostrations), during which it is recommended to say, "O Allah, forgive me, have mercy on me... Etc." Thus, what should a Muslim who wants to prolong the two Sujuds say besides this Du`a' (supplication)? May he repeat this Du`a' so that the time he sits between the two Sujuds becomes equal to that of the Sujud as in the Hadith reported on the authority of Hudhayfah and Ibn Mas`ud regarding their offering Qiyam-ul-Layl (optional Prayer at night) with the Prophet (peace be upon him)?

A: The Prophet (peace be upon him) used to say when sitting between the two Sajdahs: O Allah, forgive me, have mercy on me, heal me, guide me, and provide for me. One may repeat it thrice or say along with it any other authentically reported Du`a'.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.