Musannaf Ibn Abi Shaybah

Hazrat Abdullah bin Sharhabil narrates that Hazrat Usman came out and ordered the leveling of graves: we leveled all the graves except the grave of Umm Amr bint Usman. He asked, "Whose grave is this?" People replied, "It is the grave of Umm Amr." He ordered that it too be leveled, so it was also leveled.