Is it obligatory to run one's fingers through the hair of the hands, chest, and feet when performing ghusl?

Anyone performing ghusl from janabah (ritual impurity requiring a full bath) must rub water through all the hair on their body, whether thick or thin, and all the skin beneath it. There is no disagreement on this, based on what Asma’ narrated when she asked the Prophet, peace and blessings be upon him, about ghusl for janabah. He said: "She should take water, purify herself and perfect her purification, or reach the extent of purification, then pour it over her head and rub it until it reaches the roots of her hair, then pour water over herself." And from Ali, may Allah be pleased with him, the Prophet, peace and blessings be upon him, said: "Whoever leaves a hair’s breadth of janabah untouched by water, will be dealt with in the Fire thus and thus."