Muaz bin Jabal reported, "I was traveling with the Prophet ﷺ and one morning I found myself riding close to him as we went along, so I said, 'Messenger of Allah, tell me of a deed that will admit me to Paradise and keep me far from the Fire.'"The Prophet ﷺ replied, "You have asked me about something great, yet it is easy for whoever Allah makes it easy for. Worship Allah and associate nothing with Him, perform the prayer, pay the zakat, fast Ramadan, and make the pilgrimage to the House."Then he said, "Shall I not show you the gateways of good? Fasting is a shield, charity extinguishes sin as water extinguishes fire, and there is a man's prayer in the depth of the night."Then he recited, "Their sides shun their beds" until he reached "they used to do" [Sajdah 32:16–17].Then he said, "Shall I not tell you of the head of the whole matter, its pillar, and the summit of its hump?"Muaz said, "Yes indeed, Messenger of Allah."He said, "The head of the matter is Islam, its pillar is the prayer, and the summit of its hump is jihad."Then he said, "Shall I not tell you what holds all of that together?"Muaz said, "Yes indeed, Prophet of Allah."So he took hold of his own tongue and said, "Restrain this."Muaz said, "Prophet of Allah, are we really to be held accountable for what we say?"He answered, "May your mother be bereaved of you, Muaz. Is there anything that throws people into the Fire on their faces, or on their noses, other than the harvest of their tongues?"
حدثنا ابن أبي عمر حدثنا عبد الله بن معاذ الصنعاني عن معمر عن عاصم بن أبي النجود عن أبي وائل
كنت مع النبي ﷺ في سفر فأصبحت يوما قريبا منه ونحن نسير فقلت يا رسول الله أخبرني بعمل يدخلني الجنة ويباعدني عن النار قال لقد سألتني عن عظيم وإنه ليسير على من يسره الله عليه تعبد الله ولا تشرك به شيئا وتقيم الصلاة وتؤتي الزكاة وتصوم رمضان وتحج البيت ثم قال ألا أدلك على أبواب الخير الصوم جنة والصدقة تطفئ الخطيئة كما يطفئ الماء النار وصلاة الرجل من جوف الليل قال ثم تلا {تتجافى جنوبهم عن المضاجع} حتى بلغ {يعملون} ثم قال ألا أخبرك برأس الأمر كله وعموده وذروة سنامه قلت بلى يا رسول الله قال رأس الأمر الإسلام وعموده الصلاة وذروة سنامه الجهاد ثم قال ألا أخبرك بملاك ذلك كله قلت بلى يا نبي الله فأخذ بلسانه قال كف عليك هذا فقلت يا نبي الله وإنا لمؤاخذون بما نتكلم به فقال ثكلتك أمك يا معاذ وهل يكب الناس في النار على وجوههم أو على مناخرهم إلا حصائد ألسنتهم
[Hasan]. Ibn Majah also transmitted it in the Book of Trials, the chapter on holding back the tongue during trials, no. 3973, from Muhammad bin Abu Umar with the same wording, and the hadith has corroborating narrations.