It was narrated from 'Abdullah bin Yazid that Abu Ayyub Al-Ansari told him, that during the Farewell Pilgrimage. He prayed with the Messenger of Allah (ﷺ) Maghrib and 'Isha' prayers together at Al-Muzdalifah.
Sunan an-Nasa'i Book 6, Hadith 112
← Previous Hadith "The Messenger of Allah (ﷺ) traveled until he came to 'Arafah, where he found that the tent had pitched for him. He stayed there until the sun had passed its zenith, then he called for Al-Qaswa' which was saddled for him. When he reached the bottom of the valley he addressed the people. Then Bilal called the Adhan, then the Iqamah, then he prayed Zuhr, then he called the Iqamah, then he prayed 'Asr, and he did not offer any other prayer in between."

Sunan an-Nasa'i Book 6, Hadith 111 Next Hadith → "I was with Ibn 'Umar when he departed from 'Arafah. When he came to Jam' (Al-Muzdalifah), he combined Maghrib and 'Isha', and when he finished he said: 'The Messenger of Allah (ﷺ) did similar to this in this place.'"

Sunan an-Nasa'i Book 6, Hadith 113