Musnad Ahmad 28:601

Yahya ibn Adam narrated to us, Abu Bakr narrated to us, from Abu Ishaq, from al-Sa’ib ibn Malik, from Abdullah ibn Amr, who said: When Ibrahim, the son of the Messenger of Allah (may Allah bless him and grant him peace), passed away, the sun eclipsed. The Messenger of Allah (may Allah bless him and grant him peace) stood up and prayed two rak'ahs. He prolonged the standing, then he bowed for as long as his standing, then he prostrated for as long as his bowing. He prayed two rak'ahs in that manner, then he performed the taslim.