Abdullah bin al-Harith relates: I went to Sayyidah Umm Hani (may Allah be pleased with her), and she told me that the Messenger of Allah (peace and blessings be upon him) had prayed Salat al-Duha (the forenoon prayer). I went out and met Ibn Abbas (may Allah be pleased with them both). I said: "Come, let us go to Umm Hani." We went in to her, and I said: "Tell your cousin about the Salat al-Duha of the Prophet (peace and blessings be upon him)." She told him, and Ibn Abbas (may Allah be pleased with them both) said: "We interpret this verse as Salat al-Ishraq (the sunrise prayer), and that is Salat al-Duha."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21402