It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever gives up wearing (costly and splendid) clothing out of humility for the sake of Allah, the Mighty and Majestic, while he is able to afford it, Allah Almighty will call him on the Day of Resurrection before all of creation, until He gives him the choice to wear whichever of the garments of faith he wishes." This hadith is sahih al-isnad (its chain is authentic), but the two Shaykhs (Bukhari and Muslim) did not record it.