مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2522
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
Al-Hakam said: Sa'eed bin Jubair led us in praying Maghrib in Muzdalifah, three rak'ah's with an iqamah. Then he said the salam, then he prayed 'Isha' with two rak'ahs. Then he stated that 'Abdullah bin ‘Umar did that, and he stated that the Messenger of Allah (ﷺ) did that.
Musnad Ahmad 2534Its isnad is saheeh]