It is narrated from Hazrat Umm Salamah (may Allah be pleased with her) that she said to the Prophet (peace and blessings be upon him), "O Messenger of Allah, I am a woman whose hair is long and I have to tie it in plaits (so is it necessary to undo them when performing ghusl?)" The Prophet (peace and blessings be upon him) said, "It is sufficient for you to pour water over it three times thoroughly."