Saad bin Muaz was struck by an arrow in his median arm vein, and the Prophet ﷺ cauterized it with his own hand using a broad-headed arrow. Then it swelled up, so he cauterized it a second time.
رمي سعد بن معاذ في أكحله، فحسمه النبي ﷺ بيده بمشقص، ثم ورمت، فحسمه الثانية.