Sa'd ibn Mu'adh
Sa’d ibn Mu'adh (Arabic: سعد ابن معاذ) was the chief of the Banu Aus tribe in Medina and one of the prominent companions of Muhammad during early Medininian period who died shortly after the Battle of the Trench.
Acceptance of Islam
Sa'd adopted Islam in 622 (1 AH), when Muhammad arrived in Medina, then known as Yathrib. He was among the leading figures among the Ansar, as Muhammad had dubbed the people of Aws and Khazraj from Medina who converted to Islam.
Confrontation with Abu Jahl and start of Badr hostilities
Prior to the Battle of Badr, Sa’d had visited Mecca once to perform his Umra with his non-Muslim friend Umayah ibn Khalaf, when they came across Abu Jahl. They had an argument, and as it became heated, Sa'd threatened Abu Jahl with stopping the Meccan trade route to Syria and informed Umayah that his life was threatened by Muhammad: Narrated 'Abdullah bin Mas'ud:
Sa'd bin Mu‘ādh came to Mecca with the intention of performing 'Umra, and stayed at the house of Umaiya bin Khalaf Abi Safwan, for Umaiya himself used to stay at Sa'd's house when he passed by Medina on his way to Sham. Umaiya said to Sad, "Will you wait till midday when the people are (at their homes), then you may go and perform the Tawaf round the Ka'ba?" So, while Sad was going around the Ka'ba, Abu Jahl came and asked, "Who is that who is performing Tawaf?" Sad replied, "I am Sa'd." Abu Jahl said, "Are you circumambulating the Ka'ba safely although you have given refuge to Muhammad and his companions?" Sad said, "Yes," and they started quarreling. Umaiya said to Sa'd, "Don't shout at Abi-l-Hakam (i.e. Abu Jahl), for he is chief of the valley (of Mecca)." Sad then said (to Abu Jahl). 'By Allah, if you prevent me from performing the Tawaf of the Ka'ba, I will spoil your trade with Sham." Umaiya kept on saying to Sa'd, "Don't raise your voice." and kept on taking hold of him. Sa'd became furious and said, (to Umaiya), "Be away from me, for I have heard Muhammad saying that he will kill you." Umaiyya said, "Will he kill me?" Sad said, "Yes." Umaiya said, "By Allah! When Muhammad says a thing, he never tells a lie." Umaiya went to his wife and said to her, "Do you know what my brother from Yathrib (i.e. Medina) has said to me?" She said, "What has he said?" He said, "He claims that he has heard Muhammad claiming that he will kill me." She said, "By Allah! Muhammad never tells a lie." So when the infidels started to proceed for Badr (Battle) and declared war (against the Muslims), his wife said to him, "Don't you remember what your brother from Yathrib told you?" Umaiya decided not to go but Abu Jahl said to him, "You are from the nobles of the valley of Mecca), so you should accompany us for a day or two." He went with them and thus Allah got him killed.
Battle of Trench and Qurayza
After the Battle of the Trench in 627 (5 AH), when Medina was unsuccessfully besieged by the Meccan army, the Banu Qurayza had treacherous dealings with the enemy.  Later the Muslims laid siege to their stronghold and the Banu Qurayza surrendered unconditionally after several weeks of siege.
Several members of the Banu Aus pleaded for their old Jewish allies and agreed to Muhammad's proposal that one of their chiefs should judge the matter. Banu Qurayza, themselves appointed Sa'd, and declared they will agree with whatever was Sa'd's verdict.
Some people (i.e. the Jews of Bani bin Quraiza) agreed to accept the verdict of Sad bin Muadh so the Prophet sent for him (i.e. Sad bin Muadh). He came riding a donkey, and when he approached the Mosque, the Prophet said, "Get up for the best amongst you." or said, "Get up for your chief." Then the Prophet said, "O Sad! These people have agreed to accept your verdict." Sad said, "I judge that their warriors should be killed and their children and women should be taken as captives." The Prophet said, "You have given a judgment similar to Allah's Judgment (or the King's judgment)."
Sa'd's verdict was based on Biblical law. Sa'd had been wounded in the earlier battles, and was on the verge of death. Sa'd succumbed to the wounds and died after returning to Medina.
He dutifully served as a member of the Muslim community and even commanded military campaigns for the Prophet during his lifetime. Saad is said to have been a stern, just and passionate man, willing to impulsively fight for what he believed in. In Muslim history, he is well regarded as a noble companion who enjoyed a close relationship with the Prophet.
I heard the Prophet saying, "The Throne (of Allah) shook at the death of Saad bin Muadh." Through another group of narrators, Jabir added, "I heard the Prophet : saying, 'The Throne of the Beneficent shook because of the death of Saad bin Muadh."
http://www.usc.edu/org/cmje/religious-texts/hadith/bukhari/058-sbt.php MBC TV Series called 'OmarSeries' narrates that when Saad got injured, Prophet asked best services to be provided to him and was even called that 'Nobody in AWS is more dear to Rasool Allah than Saad'
- Sahih al-Bukhari, 5:59:286
- "Mubarakpuri, The Sealed Nectar, Chapter Al-Ahzab Invasion
- A Life of Mahomet and History of Islam to the Era of the Hegira, volume 3, page.
- Mohammed Abu-Nimer (2000–2001). "A Framework for Nonviolence and Peacebuilding in Islam". Journal of Law and Religion 15 (1–2): 247. doi:10.2307/1051519.
- Hashmi, Sohail H.; Buchanan, Allen E; Moore, Margaret (2003). States, Nations, and Borders: The Ethics of Making Boundaries. Cambridge University Press.
- Khadduri, Majid (1955). War And Peace in the Law of Islam. Baltimore: Johns Hopkins Press.
- Sahih al-Bukhari, 5:58:148
- Sahih al-Bukhari, 5:58:147