Musnad Ahmad 33:228

Hashim narrated to us, Zuhayr narrated to us, Abu al-Zubayr narrated to us, from Jabir, who said: "Sa'd ibn Mu'adh was struck in his median cubital vein, so the Messenger of Allah (peace and blessings of Allah be upon him) cauterized it with his own hand using an arrowhead. Then it swelled, so he cauterized it a second time."