It is reported about Sayyiduna Abdullah bin Salam (may Allah be pleased with him) that once he passed through the market carrying a bundle of firewood. He was asked: "Why have you done this, when Allah Almighty has made you free of need of it?" He said: "I intended to crush pride. I heard the Prophet (peace and blessings be upon him) say: 'A person in whose heart there is pride equal to a mustard seed will not enter Paradise.'"
Tabarani recorded it in al-Mu'jam al-Kabir, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الإيمان / 361