Narrated Sahl bin Sa'd:

Allah's Apostle ﷺ said, "Whoever can guarantee (the chastity of) what is between his two jaw-bones and what is between his two legs (i.e. his tongue and his private parts), I guarantee Paradise for him."

حَدَّثَنَا مُحَمَّدُ بْنُ أَبِي بَكْرٍ الْمُقَدَّمِيُّ، حَدَّثَنَا عُمَرُ بْنُ عَلِيٍّ، سَمِعَ أَبَا حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ، عَنْ رَسُولِ اللَّهِ ﷺ قَالَ
" مَنْ يَضْمَنْ لِي مَا بَيْنَ لَحْيَيْهِ وَمَا بَيْنَ رِجْلَيْهِ أَضْمَنْ لَهُ الْجَنَّةَ ".