Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) said: I said: O Messenger of Allah, tell me of a deed that will admit me into Paradise and keep me far from the Fire. He (peace and blessings be upon him) said: "You have asked about something tremendous, yet it is easy for the one for whom Allah makes it easy: that you worship Allah and do not associate anything with Him, establish the obligatory prayer, pay the obligatory zakah, and fast Ramadan. If you wish, I will also tell you about the gates of good." I said: Certainly, O Messenger of Allah! He (peace and blessings be upon him) said: "Fasting is a shield, charity wipes out sin, and a man's standing (in prayer) in the depths of the night seeking the pleasure of Allah." (The narrator said:) Then he (peace and blessings be upon him) recited this verse: "Their sides forsake their beds" [Al-Sajdah: 16].
Then he said: "If you wish, I will also tell you the head of this matter, its pillar and its highest peak." I said: Certainly, O Messenger of Allah! He (peace and blessings be upon him) said: "As for the head of the matter, it is Islam; as for its pillar, it is the prayer; and as for its highest peak, it is jihad in the path of Allah. And if you wish, I will also tell you of that which has more control over people than all of that." I said: What is it, O Messenger of Allah? He (peace and blessings be upon him) pointed his finger towards his mouth. I said: O Messenger of Allah, will we be held accountable for what we say with our tongues? He (peace and blessings be upon him) said: "May your mother be bereaved of you, O Ibn Jabal! Does anything topple people on their noses into the fire of Hell except the harvests of their tongues?"
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17428