Mishkat al-Masabih 5781

Umm Khalid daughter of Sa’id. told that once when the Prophet (ﷺ) was brought some garments among which was a small black cloak with a border he said, “Bring me Umm Khalid.” Then when she was carried to him1 he took the cloak in his hand and put it on her, saying, “Wear it out and make it ragged, then wear it out and make it clear[2].” It had a green, or a yellow, mark on it, and he said, “This is sanah, which means `beautiful’ in the language of the Abyssinians.” She said that she began to play with the seal of prophecy and that when her father rebuked her God’s messenger said, “Leave her alone.”
Indicating that she was an infant at the time.
Mirqat, 5:378, says this represents a prayer that she might live long.

Bukhari transmitted it.