How can a woman wipe her head if her hair is long and tied, and must she untie it in order to wipe over it back and forth, as stated in Fatwa No. 59455?

It is sunnah to wipe the head back and forth, based on the hadith of Abdullah ibn Zayd describing the ablution of the Prophet, peace and blessings be upon him: "He wiped his head with his hands, bringing them forward and then backward. He started from the front of his head until he took them to his nape, then he brought them back to the place from which he started." It is not obligatory for a woman to untie her braided hair; rather, she should wipe the surface of her hair back and forth. Some scholars hold that returning the hands is sunnah for someone whose hair flips over, so that the wetness reaches it; otherwise, there is no need for it. This is the view of the Shafi'i school, who do not consider the return a sunnah for a woman who has braided her hair.