Sayyiduna al-Harith bin Dirar al-Khuza'i (may Allah be pleased with him) said: I came to the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) invited me to Islam. I entered it and affirmed it. Then he (peace and blessings be upon him) called me to zakah, and I affirmed that too. I said: O Messenger of Allah, I will return to my people and invite them to Islam and to paying zakah, and whoever responds to me among them, I will collect his zakah. Then, O Messenger of Allah, send a messenger at such-and-such a time so that the zakah I have collected may reach you. The narrator said: When al-Harith (may Allah be pleased with him) had collected the zakah from those who responded to him, and the time came at which the Messenger of Allah (peace and blessings be upon him) had intended to send the messenger, the messenger was held back for some reason and did not come. Al-Harith (may Allah be pleased with him) thought that perhaps some displeasure had arisen against him from Allah and His Messenger (peace and blessings be upon him). So he summoned the chiefs of his people and said to them: The Messenger of Allah (peace and blessings be upon him) had fixed a time for me at which he would send his messenger to take the zakah that is with me, and the Messenger of Allah (peace and blessings be upon him) never breaks a promise. I do not think the holding back of his messenger is due to anything other than displeasure. Come, let us go to the Messenger of Allah (peace and blessings be upon him). The narrator said: Meanwhile, the Messenger of Allah (peace and blessings be upon him) sent al-Walid bin Uqbah to al-Harith (may Allah be pleased with him) to bring the zakah that had been collected with him. When al-Walid set out and reached part of the way, he became afraid and turned back. He came to the Messenger of Allah (peace and blessings be upon him) and said: O Messenger of Allah, al-Harith refused to give me the zakah and wanted to kill me. The narrator said: Upon this, the Messenger of Allah (peace and blessings be upon him) sent a detachment towards al-Harith. Meanwhile, al-Harith (may Allah be pleased with him) set out with his companions, until, when the detachment had left Madinah and came face to face with them, al-Harith (may Allah be pleased with him) met them. The people said: This is al-Harith. When he reached them, he asked them: To whom have you been sent? They said: To you. He asked: Why? The people said: The Messenger of Allah (peace and blessings be upon him) had sent al-Walid bin Uqbah, and he came back claiming that you refused to give the zakah and wanted to kill him. Al-Harith (may Allah be pleased with him) said: No, by the One who sent Muhammad (peace and blessings be upon him) with the truth, I neither saw him nor did he come to me. I only came because the messenger for collecting the zakah was held back from me, and I feared that it might be some displeasure from Allah and His Messenger (peace and blessings be upon him). The narrator said: Upon this, this verse of Surah al-Hujurat was revealed: "O you who believe, if a sinful person comes to you with news, then verify it, lest you harm a people out of ignorance and then become regretful over what you have done" [Surah al-Hujurat: 6] up to: "As a bounty from Allah and a favour. And Allah is All-Knowing, All-Wise" [Surah al-Hujurat: 8].
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3382