Sayyidah Umm Hani bint Abi Talib (may Allah be pleased with her) narrates that the Messenger of Allah (peace and blessings be upon him) performed eight units of Duha prayer on that day, and he would say salam after every two units.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب صلاة الضحى / 1234