It is narrated from Sayyiduna Zayd bin Arqam (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) passed by them while they were praying the forenoon (Duha) prayer, when the sun had risen, and he (peace and blessings be upon him) said: "The prayer of the oft-repentant (al-awwabin) is when the feet of the young camels begin to burn."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5091