Sunan an-Nasa'i 4988
It was narrated that Qatadah said:
"I heard Anas bin Malik narrating that the Prophet [SAW] said: 'There are three things, whoever attains them will find therein a sweetness of faith: When he loves a person, and only loves him for the sake of Allah [SWT]; when Allah [SWT] and His Messenger [SAW] are dearer to him than all else; and when he would prefer to be thrown into the fire rather to go back to the disbelief from which Allah [SWT] has saved him.'"
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ، عَنْ شُعْبَةَ، عَنْ قَتَادَةَ، قَالَ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ، رضى الله عنه يُحَدِّثُ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏
"‏ ثَلاَثٌ مَنْ كُنَّ فِيهِ وَجَدَ حَلاَوَةَ الإِيمَانِ مَنْ أَحَبَّ الْمَرْءَ لاَ يُحِبُّهُ إِلاَّ لِلَّهِ عَزَّ وَجَلَّ وَمَنْ كَانَ اللَّهُ عَزَّ وَجَلَّ وَرَسُولُهُ أَحَبَّ إِلَيْهِ مِمَّا سِوَاهُمَا وَمَنْ كَانَ أَنْ يُقْذَفَ فِي النَّارِ أَحَبَّ إِلَيْهِ مِنْ أَنْ يَرْجِعَ إِلَى الْكُفْرِ بَعْدَ أَنْ أَنْقَذَهُ اللَّهُ مِنْهُ ‏"‏ ‏.‏