While I was sitting between 'Abd Allah and Abu Musa, the latter said: Abu 'Abd al-Rahman, what do you think if a man becomes defiled (because of seminal omission) and does not find water for a month; should he not perform tayammum ? He replied: No, even if he does not find water for a month. Abu Musa then said: How will you do with the Qur'anic version (about tayammum) in the chapter al-Ma'idah which says: "... and you find no water, then go to clean, high ground" (5:6)? 'Abd Allah (b. Mas'ud) then said: If they (the people) are granted concession in this respect, they might perform tayammum with pure earth when water is cold. Abu Musa said: For this (reason) you forbade it ? He said: Yes. Abu Musa then said: Did you not hear what 'Ammar said to 'Umar ? (He said): The Messenger of Allah (ﷺ) sent me on some errand. I had seminal emission and I did not find water. Therefore, I rolled on the ground just as an animal rolls down. I then came to the Prophet (ﷺ) and made a mention of that to him. He said: It would have been enough for you to do thus. Then he struck the ground with his hands and shook them off and then stuck the right hand with his left hand and his left hand with his right hand (and wiped) over his hands (up to the wrist) and wiped his face. 'Abd Allah then said to him: Did you not see that 'Umar was not satisfied with the statement of 'Ammar ?