Is saying "Rabbi ghfir li (O Lord, forgive me)" three times between the two prostrations considered a Sunnah or an obligation in the Hanafi school of thought, and is it permissible to substitute it with another supplication? And if it is an obligation, are the previous prayers in which this supplication was not recited accepted? And is saying "Allahu Akbar (God is the Greatest)" when moving between the pillars of prayer a Sunnah or an obligation in the Hanafi school of thought?

Scholars have differed on the ruling regarding the transitional takbirat (saying "Allahu Akbar") and the supplication "Rabbighfirli" (O Lord, forgive me) between the two prostrations. The majority of jurists (Hanafis, Malikis, and Shafi'is) hold that they are Sunnah (recommended) and not obligatory, while the Hanbalis consider them obligatory. The author preponderated that the transitional takbirat are obligatory based on the evidence presented, and that the supplication between the two prostrations, "Rabbighfirli," is mustahabb (desirable) due to the absence of explicit evidence for its obligation. It is permissible to add to it or supplicate with other words.