Sahih al-Bukhari 346

Umar ibn Hafs narrated to us: My father narrated to us: al-A‘mash narrated to us: I heard Shaqiq ibn Salamah say: I was with Abd Allah and Abu Musa. Abu Musa said to him, ‘Abu Abd al-Rahman, what do you think a person should do if he becomes sexually impure and cannot find water?’ Abd Allah replied, ‘He should not pray until he finds water.’ Abu Musa said, ‘What do you make of Ammar’s report that the Prophet told him, “That would have been enough for you”?’ He replied, ‘Did you not see that Umar was not satisfied with that?’ Abu Musa said, ‘Then leave Ammar’s report aside. What do you say about this verse?’ Abd Allah did not know what to say. He then said, ‘If we granted people this concession, soon whenever the water was cold, one of them would leave it and perform tayammum.’ I asked Shaqiq, ‘Was that the reason Abd Allah disliked it?’ He said, ‘Yes.’