Zaid bin Thabit said: "We ate Sahar with the Messenger of Allah, then we stood for the Salat." I (Anas) said: "How long was that?" He said: "About the lengthy of fifty Ayahs."
Jami` at-Tirmidhi Book 8, Hadith 22
← Previous Hadith "Masruq and I entered upon Aishah and we said: 'O Mother of the Believers! There are two men from the Companions of Muhammad, one of them hastens to break the fasts and he hastens to perform Salat. The other delays breaking the fast and he delays the Salat.' She said: 'Which of them hastens to break the fast and hastens to perform the Salat?' We said that it was Abdullah bin Mas'ud. She said: 'This is how the Messenger of Allah did it.' And the other was Abu Musa."

Jami` at-Tirmidhi Book 8, Hadith 21 Next Hadith → (Another chain) except that he said: "About the length for reciting fifty Ayahs."

Jami` at-Tirmidhi Book 8, Hadith 23