Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) passed by weeping, and he (Sayyiduna Ibn Umar, may Allah be pleased with them both) asked: "Why are you weeping?" He said: "Because of a hadith which I heard from the occupant of this grave - meaning the Prophet (peace and blessings be upon him). He (peace and blessings be upon him) had said: 'Even a little showing off (riya') is shirk, and the most beloved of servants to Allah are the God-fearing and obscure, who, when they are absent, are not missed, and when they are present, are not recognised. These are the leaders of guidance and the lamps of knowledge.'"
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17189