It was narrated from Ibn 'Umar that the Prophet (ﷺ) prayed Maghrib and 'Isha' at Al-Muzdalifah.
Sunan an-Nasa'i Book 6, Hadith 114
← Previous 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 Next Hadith → "I never saw the Messenger of Allah (ﷺ) combine any two prayers except in Al-Muzdalifah, and on that day he prayed Subh before its time."

Sunan an-Nasa'i Book 6, Hadith 115