What is the legislated supplication to be recited between the two prostrations?
Chapter on the Description of Prayer
Al-Mughni
Book of Prayer
Primary text
The recommended (Mustahabb) statement between the two prostrations, according to Abu Abdullah (Ahmad), is repeating the phrase, "Rabbighfirli, Rabbighfirli" (My Lord, forgive me, My Lord, forgive me). The minimum obligatory amount is to say it once. The degree of perfection (Adna al-Kamal) is saying it three times, and complete perfection aligns with the established differing narrations concerning the extent of glorification in bowing and prostration.
Supporting text
It is narrated from Ibn Abbas that the Prophet (peace be upon him) used to say between the two prostrations: "Allahumma-ghfirli, warhamni, wahdini, wa 'afini, warzuqni" (O Allah, forgive me, have mercy upon me, guide me, grant me well-being, and provide for me). It is permissible to substitute "Rabbighfir lana" or "Allahumma-ghfir lana" in place of "Rabbighfirli."