Umm Hani's Protection, and the Duha Prayer

Shaykh Yasir Qadhi explains:

Among the last converts was Umm Hāniʾ bint Abī Ṭālib, cousin of the Prophet ﷺ and full sister of ʿAlī, who accepted Islam at the Conquest. Two of her in-laws, having fled fearing ʿAlī's revenge over an old quarrel, took refuge in her house; she barred the door against her own brother and kept them safe. Enraged, ʿAlī threatened them, so at dawn she went straight to the Prophet ﷺ. He was taking a ghusl behind a cloth his daughter Fāṭimah held up; hearing it was his cousin, he lowered the screen and said, مَرْحَبًا بِأُمِّ هَانِئ, "Welcome, Umm Hāniʾ." When she told her story he said, "We grant protection to whomever you protect."

From this the scholars draw the law of amān: any Muslim at all, man or woman, free or slave, may grant a personal protection that binds the whole community, a strikingly open system without precedent. And Umm Hāniʾ added that she saw the Prophet ﷺ pray eight rakʿahs of Ṣalāt al-Ḍuḥā that morning, the only report of him praying it, for he kept it to the privacy of his house. Its time runs from after sunrise until just before Ẓuhr, best prayed when the heat begins; two rakʿahs suffice, four is the measure of excellence ("pray four at the day's start and I will suffice you to its end"), and eight is what the Prophet ﷺ prayed.