From Mu'adh bin Jabal رضي الله عنه who said: I said:
"O Messenger of Allah, tell me of a deed which will take me into Paradise and will keep me away from the Hell-fire." He said: "You have asked me about a great matter, yet it is, indeed, an easy matter for him to whom Allah Almighty makes it easy. (It is ) that you worship Allah without associating anything with Him, that you perform the prayers, that you pay the zakat, that you fast during Ramadan, and that you make the pilgrimage to the House."
Then he said: "Shall I not guide you to the gates of goodness? Fasting is a shield; charity extinguishes sin as water extinguishes fire; and a man's prayer in the middle of the night." Then he recited:
تَتَجَافَى جُنُوبُهُمْ عَنِ الْمَضَاجِعِ يَدْعُونَ رَبَّهُمْ خَوْفًا وَطَمَعًا وَمِمَّا رَزَقْنَاهُمْ يُنفِقُونَ
فَلَا تَعْلَمُ نَفْسٌ مَّا أُخْفِيَ لَهُم مِّن قُرَّةِ أَعْيُنٍ جَزَاء بِمَا كَانُوا يَعْمَلُونَ
"Who forsake their beds to cry unto their Lord in fear and hope, and spend of that We have bestowed on them. No soul knoweth what is kept hid for them of joy, as a reward for what they used to do."
[Surah al-Sajdah 32: 16-17]
Then he said: "Shall I not also tell you of the peak of the matter, its pillar, and its topmost part?" I said: "Yes, O Messenger of Allah." He said: "The peak of the matter is Islam (submission to Allah), the pillar is prayer; and its topmost part is jihad." Then he said: "And shall I not tell you of the controlling of all that?" I said: "Yes, O Messenger of Allah". So he took hold of his tongue and said: "Restrain this." I said: "O Prophet of Allah, will we be held accountable for what we say?" He said: "May your mother be bereft of you! Is there anything that topples people on their faces (or he said, on their noses) into the Hell-fire other than the jests of their tongues?"
Related by Al-Tirmidhi, who said it was a fine and sound.