Zayd bin Arqam reported,

I was on a military expedition when I heard Abdullah bin Ubayy say, "Do not spend on those who are with the Messenger of Allah, so that they may disperse from around him. And if we return from this expedition, the most honorable will surely expel the most lowly from it."I mentioned this to my uncle, or to Umar, who reported it to the Prophet ﷺ. The Prophet ﷺ summoned me, and I told him what I had heard. The Messenger of Allah ﷺ then sent for Abdullah bin Ubayy and his companions, and they swore that they had not said it. So the Messenger of Allah ﷺ disbelieved me and believed them.I was overcome with such grief as I had never felt before, and I confined myself to my house. My uncle said to me, "What did you hope to achieve, except that the Messenger of Allah ﷺ would call you a liar and despise you?"Then Allah Almighty revealed, "When the hypocrites come to you" [Munafiqun 63:1]. The Prophet ﷺ sent for me and recited it, then said, "Allah has confirmed your truthfulness, Zayd."

عن زيد بن أرقم قال

كنت في غزاة، فسمعت عبد الله بن أبي يقول: لا تنفقوا على من عند رسول الله حتى ينفضوا من حوله، ولئن رجعنا من عنده ليخرجن الأعز منها الأذل. فذكرت ذلك لعمي- أو لعمر-، فذكره للنبي ﷺ، فدعاني فحدثته، فأرسل رسول الله ﷺ إلى عبد الله بن أبي وأصحابه فحلفوا ما قالوا، فكذبني رسول الله ﷺ وصدقه، فأصابني هم لم يصبني مثله قط، فجلست في البيت، فقال لي عمي: ما أردت إلى أن كذبك رسول الله ﷺ ومقتك، فأنزل الله تعالى: {إذا جاء ك المنفقون} [المنافقون: ١]، فبعث إلي النبي ﷺ فقرأ فقال: إن الله قد صدقك يا زيد.