Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) combined Maghrib and Isha at Muzdalifah on the occasion of the Farewell Hajj.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9490