I am (at times) affected by seminal emission but find no water. He ('Umar) told him not to say prayer. 'Ammar then said. Do you remember,0 Commander of the Faithful, when I and you were in a military detachment and we had had a seminal emission and did not find water (for taking bath) and you did not say prayer, but as for myself I rolled in dust and said prayer, and (when it was mentioned before) the Apostle (ﷺ) said: It was enough for you to strike the ground with your hands and then blow (the dust) and then wipe your face and palms. Umar said: 'Ammar, fear Allah. He said: If you so like, I would not narrate it. A hadith like this has been transmitted with the same chain of transmitters but for the words: 'Umar said: We hold you responsible for what you claim."
The Book of Menstruation - Sahih Muslim 368 c
This narration from Sahih Muslim addresses the important matter of purification when water is unavailable. The companion 'Ammar ibn Yasir relates an incident where both he and 'Umar experienced seminal emission during a military expedition without access to water for purification.
Scholarly Commentary on Tayammum
The Prophet Muhammad (ﷺ) taught 'Ammar that when water is unavailable, one may perform tayammum (dry ablution) by striking the earth with one's hands, blowing off excess dust, and then wiping the face and hands. This demonstrates Allah's mercy in facilitating worship even in difficult circumstances.
The exchange between 'Umar and 'Ammar illustrates how even senior companions could have differing understandings of religious rulings, and how proper knowledge must be established through authentic transmission from the Prophet (ﷺ).
Legal Implications
This hadith establishes tayammum as a valid substitute for ritual purification when water is genuinely unavailable or its use would cause harm. The method described - striking clean earth, removing excess dust, and wiping face and hands - constitutes the proper form of dry ablution.
The narration also shows that seminal emission requires full purification (ghusl), and when water is unavailable, tayammum suffices to permit prayer until water becomes available.