On the day of Al-Khandag (battle of the Trench), the medial arm artery or vein of Sa'd (bin) was injured and the Prophet (ﷺ) pitched a tent in the mosque to look after him. There was another tent for Banî Ghifar in the mosque and the blood started flowing from Sa'd's tent to the tent of Banî Ghifar. They shouted, "O occupants of the tent ! What is coming from you to us?" They found that Sa'd's wound was bleeding profusely and Sa'd died in his tent. [1:452-O.B.]