On the authority of Abū Muʿādh ibn Jabal (raḍī Allāhu ʿanhu) who said:
I said: O Messenger of Allāh, tell me an act which will take me into Paradise and will keep me away from the Hell-fire.
He said: You have asked me about a major matter, yet it is easy for him for whom Allāh, the Exalted, makes it easy. You should worship Allāh, associating nothing with Him; you should perform the prayers; you should pay the zakat, you should make the pilgrimage to the House. Then he said: Shall I not show you the gates of goodness? Fasting [which] is a shield; charity extinguishes sin as water extinguishes fire; and the praying of the man in the depths of the night. then he recited: their sides forsake their beds invoking their Rubb in fair and hope and they spend out of what we have bestowed on them. No person knows what is kept hidden for them of joy as a reward for what they used to do. Then he said: Shall I not tell you of the peak of the matter its pillar and its topmost part?
I said: Yes, O Messenger of Allāh.
The peak of matter is Islām, the pillar is prayer, and its topmost part is jihād. Then he said: Shall I not tell you of the controlling of all that? I said Yes, O Messenger of Allāh. And he took hold of his tongue and said: Restrain this.
I said: O Prophet of Allāh, will what we say be held against us? He said: May your mother be bereaved of you O Muʿādh! Is there anything that topples people on their faces -or he said on their nose- into Hell-fire other than the harvests of their tongues?
It was related by al-Tirmidhī, who stated that as a ḥasan (fair) and ṣaḥīḥ (sound) ḥadīth
Source: An-Nawawi’s Forty Ḥadīth