How should a person with a bandage, cast, or wound on their body or limb perform ablution?

If washing a broken or injured limb would harm the wound or delay its healing, it is sufficient to wipe (masḥ) once over the cast, bandage, or cotton tied with something during ablution (wudu) or ritual washing (ghusl). The legitimacy of wiping over a bandage is established by the Sunnah. ʿAli (ra) said: “One of my wrists was broken. I asked the Prophet (s.a.s.) and he instructed me to wipe over the bandages.” (Ibn Mājah, Ṭahārah, 134 [657] 4)

If there is a bandage due to a fracture, dislocation, or wound on any part of the body, and it does not harm the wound to remove the bandage, then the area beneath should be washed and the wound itself wiped over. However, if removing the bandage would be harmful, it may be wiped over without removal.

One wiping over the bandage is sufficient. With this act, the limb is considered ritually washed. It does not matter if the bandage was applied while in a state of minor or major ritual impurity, and there is no specific time limit for wiping over the bandage; it may be wiped over until the wound or fracture heals. If wiping itself becomes harmful, it is also omitted. (Kāsānī, Badā’iʿ, 1/13-14)

If the bandage or cast covers most of the limbs required for ablution or ghusl, then dry ablution (tayammum) is performed instead. (Ibn ʿĀbidīn, Radd al-Muḥtār, 1/102, 260, 280 ff.) “If you are in a state of major impurity, purify yourselves. But if you are ill or on a journey, or one of you comes from the toilet, or you have touched women (had sexual intercourse) and you find no water, then perform tayammum with clean earth and wipe your faces and hands with it.” (al-Māʾidah, 5/6) This verse indicates that tayammum may be performed in such situations.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu