Jami` at-Tirmidhi 2658

Narrated 'Abdul-Malik bin 'Umair:from 'Abdur-Rahman bin 'Abdullah bin Mas'ud that he narrated from his father, from the Prophet (ﷺ) who said: "May Allah beautify a man who hears a saying of mine, so he understands it, remembers it, and conveys it. Perhaps he carries the Fiqh to one who has more understanding than him. There are three with which the heart of a Muslim shall not be deceived. Sincerity in deeds for Allah, giving Nasihah to the A'immah of Muslims, and sticking to the Jama'ah. For indeed the call is protected from behind them