Sayyiduna Jarir (may Allah be pleased with him) said: "I saw the Messenger of Allah (peace and blessings be upon him) standing at Arafah, with his cloak tucked under his arm, raising both his hands, which did not go higher than his head, and the muscles of both his arms (peace and blessings be upon him) were trembling."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2373