When sitting between two Sujood (Prostrations) – 1

رَبِّ اغْفِرْ لِي رَبِّ اغْفِرْ لِي

Rabbighfir lee, Rabbighfir lee

Lord, forgive me. My Lord, forgive me.

An-Nasa’i: 1146, 1666 Abu Dawud: 874