Mu'adh bin Jabal (May Allah be pleased with him) reported:

I asked the Messenger of Allah (ﷺ): "Inform me of an act which will cause me to enter Jannah and keep me far from Hell." He (ﷺ) replied, "You have asked me about a matter of great importance, but it is easy for one for whom Allah makes it easy." He added, "Worship Allah, associate nothing with Him in worship, offer As-Salat (the prayer), pay the Zakat, observe Saum (fasting) during Ramadan and perform Hajj (pilgrimage) to the House of Allah, if you can afford it." He (ﷺ) further said, "Shall I not guide you to the gates of goodness? Fasting is a screen (from Hell), charity extinguishes (i.e., removes) the sins as water extinguishes fire, and standing in prayers by a slave of Allah during the last third part of the night." Then he recited: "Their sides forsake their beds, to invoke their Rabb in fear and hope, and they spend (in charity in Allah's Cause) 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." (32:16-17) Then he added, "Shall I tell you of the root of the matter, its pillar and its highest point?" I replied: "Yes! Certainly, O Prophet (ﷺ) of Allah." He said, "The root of this matter (foundation) is Islam, its pillar (mainstay is) As-Salat (the prayer) and its highest point is Jihad (fighting in the Cause of Allah)." Then he asked, "Shall I tell you of that which holds all these things?" I said: "Yes, O Messenger of Allah." So he took hold of his tongue and said, "Keep this in control." I asked: "O Messenger of Allah! Shall we really be accounted for what we talk about?" He replied, "May your mother lose you! People will be thrown on their faces into the Hell on account of their tongues."

وعن معاذ رضي الله عنه قال‏:‏ قلت يا رسول الله‏:‏ أخبرني بعمل يدخلني الجنة، ويباعدني من النار‏؟‏ قال‏:‏ ‏"‏لقد سألت عن عظيم، وإنه ليسير على من يسره الله تعالى عليه‏:‏ تعبد الله لا تشرك به شيئًا، وتقيم الصلاة، وتؤتي الزكاة، وتصوم رمضان وتحج البيت إن استطعت إليه سبيلا ثم قال‏:‏ ألا أدلك على أبواب الخير‏؟‏ الصوم جُنة، والصدقة تطفئ الخطيئة كما يطفئ الماء النار، وصلاة الرجل من جوف الليل” ثم تلا‏:‏ ‏{‏تتجافى جنوبهم عن المضاجع‏}‏ حتى بلغ‏:‏ ‏{‏يعملون‏}‏ ‏(‏‏(‏السجدة‏:‏ 16-17‏)‏‏)‏‏.‏ ثم قال‏:‏ ‏"‏ألا أخبرك برأس الأمر وعموده وذِروة سنامه‏"‏ قلت‏"‏ بلى يا رسول الله، قال‏:‏ رأس الأمر الإسلام، وعموده الصلاة، وذِروة سنامه الجهاد” ثم قال‏:‏ “ألا أخبرك بملاك ذلك كله‏؟‏‏"‏ قلت‏:‏ بلى يا رسول الله، فأخذ بلسانه قال‏:‏ ‏"‏كف عليك هذا‏"‏ قلت‏:‏ يا رسول الله وإنا لمؤاخذون بما نتكلم به‏؟‏ فقال‏:‏ ثكلتك أمك‏!‏ وهل يُكب الناس في النار على وجوههم إلا حصائد ألسنتهم‏؟‏‏"‏ ‏(‏‏(‏رواه الترمذي وقال‏:‏ حديث حسن صحيح، وقد سبق شرحه في باب قبل هذا‏)‏‏)‏‏.‏