She said:
One day God's Messenger visited me looking pleased and asked if I was not surprised to hear that Mujazziz al-Mudlijl1 had entered, and seeing Usama and Zaid2 with a rug over them covering their heads and letting their feet appear, said, “These feet are related.”
(Bukhari and Muslim.)
1. Members of the tribe of Mudlij were said to have a reputation for being able to trace relationship from physical features.
2. Usama was Zaid's son.