Sahih Muslim Book 3, Hadith Number 719.

Chapter : Tayammum.

‘Abd al-Rahman b. Abza narrated it on the authority of his father that a man came to Umar and said: I have had a seminal emission but I found no water, and the rest of the Hadith is the same but with this addition: ‘Amr said: O Commander of the Faithful, because of the right given to you by Allah over me, if you desire, I would not narrate this Hadith to anyone.