Umar ibn al-Khattab · The Book on Salat (Prayer)

"Allah's Messenger would talk during the night with Abu Bakr about matters concerning the Muslims while I was with them."

"On the Day of Al-Khandaq (the battle of the Trench), Umar bin Al-Khattab came cursing the disbelievers of Quraish and said: 'O Allah's Messenger! I could not offer he Asr prayer until the sun was about to set.' The Prophet said: 'By Allah! I too have not offered the Salat.'" So he said: "We descended into Buthan, Allah's Messenger performed Wudu and we too performed Wudu. Allah's Messenger prayed Asr after the sun had set, then after it he prayed…

Same as 255 (above) with a different chain

"Umar bin Al-Khattab said to us: 'The knees are the Sunnah for you, so hold the knees.'"