It is narrated from Sayyiduna Sa’d bin Abi Waqqas (may Allah be pleased with him) that I saw the Messenger of Allah (peace and blessings be upon him) turning (his head) to the right and to the left while saying salam.
Hadith Referenceمسند احمد / مسند باقي العشرة المبشرين بالجنة / 1619