Mukhtasar Bukhari

Umm al-Mu'mineen Aisha Siddiqa (may Allah be pleased with her) says that on the day of (the Battle of) Khandaq, Sayyiduna Sa'd (may Allah be pleased with him) was wounded in the median vein (a name of a vein), so the Noble Prophet (peace and blessings be upon him) set up a tent in the mosque so that he could visit him closely. Then suddenly, while there was also a tent of Banu Ghifar in the mosque, blood started flowing towards them, so those people said, "O people of the tent! What is this that is coming to us from your side?" (When they looked,) they saw that blood was flowing from the wound of Sayyiduna Sa'd (may Allah be pleased with him), and thus he was martyred from this wound.