In the two Ṣaḥīḥ collections it is related from Abū Hurayrah (may Allah be pleased with him) that he said:
“I heard the Messenger of Allah—peace and blessings be upon him—say: ‘While I was asleep I saw myself beside a well over which hung a bucket. I drew water from it as much as Allah willed; then the son of Abū Quḥāfah (Abū Bakr) took hold of it and drew one or two bucketfuls, yet his drawing was somewhat weak—may Allah forgive him. The bucket then turned into a large leather bucket, and the son of al-Khaṭṭāb (‘Umar) seized it. I have never seen any man draw water the way ‘Umar did, until the people watered their animals and rested.’
In another wording: ‘The bucket turned into a large one in ‘Umar’s hand.’
Al-Shāfiʿī said: ‘It was a dream vision.’