Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) narrates: I asked the Prophet Muhammad (peace be upon him) about the bandage that is tied over a wound—how should such a person perform ablution, and if he becomes in a state of major impurity, how should he perform ghusl? The Prophet (peace be upon him) said:“Such a person should wipe over it with water in the state of major impurity.”Then I asked: What if it is cold or there is fear for his life? The Prophet (peace be upon him) said:“He should wipe over his whole body.”Then he recited this verse:“Do not kill yourselves; indeed, Allah is merciful to you.”He said:“If such a person fears (harm), then he should perform tayammum.”