Sayyiduna Ali (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "The protection granted by all the Muslims is the same; even the lowest of them may grant protection. Whoever violates the protection granted by a Muslim, upon him is the curse of Allah, the angels and all the people; neither his obligatory nor his voluntary deeds will be accepted. And whoever takes a believer as his patron without the permission of his own patrons, upon him is the curse of Allah, the angels and all the people; neither his obligatory nor his voluntary deeds will be accepted." (b) Sayyiduna Ali (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him): "The blood of all the believers is equal; they are united like one hand against those opposed to them, and even the lowest of them may grant protection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18168
Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "Even the lowest person of my Ummah may grant protection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18169
Fudayl bin Zayd (may Allah have mercy on him) says: We were lined up facing the enemy. He says: A slave wrote a guarantee of safety for the idolaters on an arrow and shot it to them. The idolaters came and said: "You have granted us safety." The Companions (may Allah be pleased with them) said: "We did not grant you safety; it was a slave who granted you safety." So they wrote to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) about it, and Sayyiduna Umar (may Allah be pleased with him) replied: "The slave is one of the Muslims; his protection counts as the protection of the Muslims." And so Sayyiduna Umar (may Allah be pleased with him) granted the idolaters safety.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18170
Ziyad bin Muslim (may Allah have mercy on him) says that a man from India came under the protection of a slave, and then a man from among the Muslims killed him. The narrator says: Umar bin Abd al-Aziz (may Allah have mercy on him) sent his blood money to his heirs.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18171
Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "From the spoils, a slave is given only low-value goods, and his grant of protection is valid when he gives people protection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السير / 18172