Chapter on Tayammum and Its Rules

And through this chain of transmission from Hammad, from Hariz, from Muhammad ibn Muslim, who said: I asked Abu ‘Abdullah عليه السلام about a man who becomes in a state of janabah in a cold land and cannot find water, or perhaps the water is frozen. Imam عليه السلام said: "He must perform ghusl regardless of the circumstances." A man informed Imam عليه السلام that he had done so and fell ill for a month due to the cold. Imam عليه السلام replied: "He performed ghusl regardless, for ghusl is obligatory." Abu ‘Abdullah عليه السلام further mentioned: "I was in a situation where I was compelled to do so while I was ill, and they brought me heated water, so I performed ghusl." Imam عليه السلام also said: "Ghusl is indispensable."