Sahih Muslim 2639 a
Anas b. Malik reported that a desert Arab said to Allah's Messenger (ﷺ):
When would be the Last Hour? Allah's Messenger (ﷺ) said: What preparation have you made for that? Thereupon he said: The love of Allah and of His Messenger (that is my preparation for the Last Hour) (for the Day of Resurrection). Thereupon he (the Holy Prophet) said: You would be along with one whom you love.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ بْنِ قَعْنَبٍ، حَدَّثَنَا مَالِكٌ، عَنْ إِسْحَاقَ بْنِ عَبْدِ اللَّهِ بْنِ،
 أَبِي طَلْحَةَ عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ أَعْرَابِيًّا، قَالَ لِرَسُولِ اللَّهِ صلى الله عليه وسلم مَتَى السَّاعَةُ
 قَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَا أَعْدَدْتَ لَهَا ‏"‏ ‏.‏ قَالَ حُبَّ اللَّهِ وَرَسُولِهِ ‏.‏
 قَالَ ‏"‏ أَنْتَ مَعَ مَنْ أَحْبَبْتَ ‏"‏ ‏.‏