It is narrated from Sayyiduna Zayd bin Arqam (may Allah be pleased with him); he said: The Messenger of Allah (peace and blessings be upon him) entered the Quba' mosque and saw them praying the forenoon (Duha) prayer, and he (peace and blessings be upon him) said: "This is the prayer of the oft-repentant (al-awwabin)."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5093