Al-Qasim al-Shaybani (may Allah have mercy on him) said that Sayyiduna Zayd bin Arqam (may Allah be pleased with him) saw some people praying the Duha prayer in the Mosque of Quba and said: Yet they know that praying at a time other than this is better. The Messenger of Allah (peace and blessings be upon him) said: "The time of the prayer of the awwabin (those who constantly turn to Allah) is when the feet of the young camels begin to burn." And once he said: when people were praying.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4908