Sayyiduna Anas bin Malik (may Allah be pleased with him) says: I saw the Prophet (peace and blessings be upon him) offering six rak'ahs in the Duha prayer, and after that I never abandoned these rak'ahs.
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains Sa'id bin Maslamah al-Umawi, whom al-Bukhari (may Allah have mercy on him), Yahya bin Ma'in and a group declared da'if (weak), while Ibn Hibban mentioned him in the book "al-Thiqat" and said: He makes mistakes.