The narration reported by Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, from Abu al-Qasim Ja‘far ibn Muhammad, from Muhammad ibn Ya‘qub, from al-Husayn ibn Muhammad, from Mu‘alla ibn Muhammad, from al-Washsha’, from Aban ibn Uthman, from Abdullah ibn Asim, who said: I asked Abu Abdullah عليه السلام about a man who does not find water and performs tayammum. While he is in prayer, a servant comes and says: 'Here is water.' Imam عليه السلام said: 'If he has not yet bowed (rukuʿ), he should leave the prayer and perform ablution (wudu’). But if he has already bowed, he should continue his prayer.'"