كتاب الإيمان
1
The Book of Faith
(85)
Chapter: Regarding the saying of the Prophet (saws): "I will be the first of the people to intercede concerning Paradise, and I will be the Prophet with the Greatest Number of Followers."
(85)
باب فِي قَوْلِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَنَا أَوَّلُ النَّاسِ يَشْفَعُ فِي الْجَنَّةِ وَأَنَا أَكْثَرُ الأَنْبِيَاءِ تَبَعًا»

Anas b. Malik reported:

The Messenger of Allah (ﷺ) said: I will come to the gate of Paradise on the Day of Resurrection. and would seek its opening. and the keeper would say: Who art thou? I would say: Muhammad. He would then say: It is for thee that I have been ordered, and not to open it for anyone before thee.
وَحَدَّثَنِي عَمْرٌو النَّاقِدُ، وَزُهَيْرُ بْنُ حَرْبٍ، قَالاَ حَدَّثَنَا هَاشِمُ بْنُ الْقَاسِمِ، حَدَّثَنَا سُلَيْمَانُ بْنُ الْمُغِيرَةِ، عَنْ ثَابِتٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ آتِي بَابَ الْجَنَّةِ يَوْمَ الْقِيَامَةِ فَأَسْتَفْتِحُ فَيَقُولُ الْخَازِنُ مَنْ أَنْتَ فَأَقُولُ مُحَمَّدٌ ‏.‏ فَيَقُولُ بِكَ أُمِرْتُ لاَ أَفْتَحُ لأَحَدٍ قَبْلَكَ ‏"‏ ‏.‏
Reference : Sahih Muslim 197
In-book reference : Book 1, Hadith 394
USC-MSA web (English) reference : Book 1, Hadith 384
  (deprecated numbering scheme)