The prohibition of killing envoys

Abu Wa'il narrates: When Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) had Ibn al-Nawwahah killed, he said at that time: This man and Ibn Uthal had both come to the Prophet (peace and blessings be upon him) as envoys of Musaylimah the Liar. The Prophet (peace and blessings be upon him) asked the two of them: "Do you both bear witness that I am the Messenger of Allah?" The two of them replied: "We bear witness that Musaylimah is the Messenger of Allah." The Prophet (peace and blessings be upon him) said: "If I were to have any delegate (that is, envoy) killed, I would have had both your necks struck." The narrator states: After this the Sunnah was established that envoys are not killed. As for Ibn Uthal, Allah Almighty sufficed us against him (that is, he died); as for this man (that is, Ibn al-Nawwahah), he remained continually in that state until Allah Almighty has now given us power over him. (Allamah Haythami says:) I say:
Abu Dawud recorded it in abridged form.
Ahmad and al-Bazzar recorded it; Abu Ya'la recorded it as a lengthy report. The chain of these authorities is hasan (good).

Ibn Mu'ayz al-Sa'di narrates: I went out before dawn to water my horse, and I passed by the mosque of Banu Hanifah while they were saying: "Musaylimah is the Messenger of Allah." I came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and told him about it. He sent the guards, and they seized those people and brought them. Sayyiduna Abdullah (may Allah be pleased with him) called (those people) to repentance; they repented, so Sayyiduna Abdullah (may Allah be pleased with him) let them go. Sayyiduna Abdullah (may Allah be pleased with him) had Ibn al-Nawwahah (from among them) killed. The people said: "You seized all of them for one and the same matter, then you had one of them killed and let the others go?" Sayyiduna Abdullah (may Allah be pleased with him) said: I heard the Prophet (peace and blessings be upon him) when this man and Ibn Uthal bin Hajar came to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) asked: "Do you both bear witness that I am the Messenger of Allah?" The two of them replied: "Do you bear witness that Musaylimah is the Messenger of Allah?" The Prophet (peace and blessings be upon him) said: "I believe in Allah Almighty and His true (and real) Messengers. If I were to have any envoy killed, I would have had the two of you killed." (Sayyiduna Abdullah (may Allah be pleased with him) said:) It is for this reason that I have killed this man. (Allamah Haythami says:) I say:
Abu Dawud recorded it in abridged form.
Ahmad recorded it. I do not know the narrator named Ibn Mu'ayz; the rest of its narrators are thiqat (trustworthy). It has another route which is more complete than this, and it will come in Kitab al-Hudud.

Sayyiduna Nu'aym bin Mas'ud (may Allah be pleased with him) narrates: Two envoys of Musaylimah came to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said: "Were it not the established practice that envoys are not killed, I would have had both your necks struck." He sent this letter with the two of them: "This is from Sayyiduna Muhammad, the Messenger of Allah (peace and blessings be upon him), to Musaylimah the Liar. To proceed: The earth belongs to Allah Almighty; He makes whomever He wills of His servants inherit it, and the good end is for the God-fearing." The narrator states: The Prophet (peace and blessings be upon him) said: "The Hour will not be established until thirty liars appear, all of them claiming that they are prophets." (Allamah Haythami says:) I say: Abu Dawud recorded it in abridged form.
Tabarani recorded it by way of Ibn Ishaq, who says: "A shaykh from Ashja' narrated this hadith to me." He did not hear it from him. Abu Dawud named that shaykh as Sa'd bin Tariq. The rest of its narrators are thiqat (trustworthy).

Wabr bin Mushhir narrates: Musaylimah sent me, Ibn Shalghaf and Ibn al-Nawwahah to the Prophet (peace and blessings be upon him). We came to him. My two companions spoke before me, because both of them were older than me. They recited the testimony of faith and then said: "We bear witness that you are a Prophet, and that after you Musaylimah (will be a prophet)." The Prophet (peace and blessings be upon him) asked (me): "O boy! What do you say?" I said: "I bear witness to what you bear witness to, and I declare false what you declare false." The Prophet (peace and blessings be upon him) said: "I bear witness, as many times as the grains of soil of al-Dahna', that Musaylimah is a liar." Then he said: "Seize the two of them." They were seized, and it was ordered that they be kept in the house of Kaysan. One of his Companions interceded for them, so the Prophet (peace and blessings be upon him) let them both go.
Tabarani recorded it. Its chain contains a group of narrators whom I do not know.