It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) combined the Maghrib and Isha prayers at Muzdalifah.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5287
Hadith Gradingحکم دارالسلام:إسناده صحيح ، م : 1287 .