Sayyiduna Zayd bin Arqam (may Allah be pleased with him) narrates: I was with my uncle on a military expedition, and I heard Abdullah bin Ubayy saying: "Do not spend on those who are with the Messenger of Allah (peace and blessings be upon him) until they disperse from around him" [al-Munafiqun: 7], "If we return to Madinah, the more honourable will surely drive out the more humble from it" [al-Munafiqun: 8]. I mentioned this to my uncle, and he mentioned it to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) called me, then the Prophet (peace and blessings be upon him) sent a messenger to Abdullah bin Ubayy bin Salul and his associates, and they swore that they had not said it. So the Messenger of Allah (peace and blessings be upon him) disbelieved me and believed him. Such grief came upon me as had never come upon me before, and I sat in the house. My uncle said to me: All you wanted was that the Prophet (peace and blessings be upon him) call you a liar and be displeased with you. Then Allah, the Mighty and Majestic, revealed: "When the hypocrites come to you" [al-Munafiqun: 1]. So the Messenger of Allah (peace and blessings be upon him) sent for me; he (peace and blessings be upon him) recited it, then said: "Indeed Allah, the Mighty and Majestic, has confirmed your truthfulness."
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5032