Al-Matalib al-'Aliyah 644 — The Duha prayer

It is narrated from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that he said: "Whoever comes to an open and wide expanse of land and performs two rak'ahs of the Duha prayer there, then says this supplication: 'Allahumma lakal-hamd, asbahtu abdaka ala ahdika wa wa'dika, anta khalaqtani wa lam aku shay'a, astaghfiruka li-dhanbi, fa-innahu qad arhaqatni dhunubi wa ahatat bi, illa an taghfiraha li, faghfirha ya arhamar-rahimin' (O Allah, all praise is for You. I have entered the morning as Your servant, (standing) upon Your covenant and promise. You created me when I was nothing worth mentioning. I seek Your forgiveness for my sin, for my sins have weighed me down and surrounded me, unless You forgive them for me; so forgive them, O Most Merciful of the merciful), then Allah Almighty forgives his sins in that very sitting, even if they are equal to the foam of the sea."
This narration is in Musnad Ishaq bin Rahwayh (644). In its chain is a narrator named Abu Qurrah al-Asadi, whose reliability has been disputed by the hadith scholars; however, the words of the supplication are established by other sahih hadith (such as Sayyid al-Istighfar).