Bulugh al-Maram: Hadith 65

concerning the verse, "And if you are ill or on a journey..." (an-Nisa': 43). He said, "If a man sustains a wound, which he suffered during Jihad (in the cause of Allah) or ulcers, then he became junub (sexually impure) and is afraid that if he bathes he would die; he may perform ablution with clean earth (Tayammum). [Reported by Ad- Daraqutni in a Mawquf (untraceable) Hadith and Al-Bazzar in a Marfu' (traceable) one. Ibn Khuzaima and Al-Hakim graded it Sahih (sound)].