The freed slave of Usama bin Zaid said, "Al-Hajjaj bin Aiman bin Um Aiman and Aiman Ibn Um Aiman was Usama's brother from the maternal side, and he was one of the Ansar. He was seen by Ibn 'Umar not performing his bowing and prostrations in a perfect manner. So Ibn 'Umar told him to repeat his prayer.
The chain is ordered from the source of the saying to the compiler: 1 = the speaker/first transmitter, the following links those who passed it on in turn, and at the bottom al-Bukhari who compiled the work. Click a narrator to list every hadith in which he appears; the number in parentheses is how many hadiths across the collections on this site the narrator appears in.