Musnad Ahmad 1156:7

Sufyan narrated to us, from Ayyub ibn Musa, from Sa’id—meaning al-Maqburi—from Abdullah ibn Rafi’, and he is the freed slave of Umm Salamah—thus Sufyan said—that she said: "O Messenger of Allah, I am a woman who binds the braids of my hair tightly." He said: "It suffices you to pour water over it three times."