Abu al-Zubair says that I asked Sayyiduna Jabir (may Allah be pleased with him): Did the Prophet (peace and blessings be upon him) combine the Maghrib and Isha prayers? He replied: Yes, during the time when we fought against Banu Mustaliq.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 14749
Hadith Gradingحکم دارالسلام:إسناده ضعيف لسوء حفظ ابن لهيعة، وأنظر: 14274