Language:
كتاب العلم
3  
Knowledge
(49)
Chapter: Whoever selected some people to teach them (religious) knowledge preferring them over others for fear that the others may not understand it
(49)
باب مَنْ خَصَّ بِالْعِلْمِ قَوْمًا دُونَ قَوْمٍ كَرَاهِيَةَ أَنْ لاَ يَفْهَمُوا
Sahih al-Bukhari 129

Narrated Anas:

I was informed that the Prophet (ﷺ) had said to Mu`adh, "Whosoever will meet Allah without associating anything in worship with Him will go to Paradise." Mu`adh asked the Prophet, "Should I not inform the people of this good news?" The Prophet (ﷺ) replied, "No, I am afraid, lest they should depend upon it (absolutely).

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا مُعْتَمِرٌ، قَالَ سَمِعْتُ أَبِي قَالَ، سَمِعْتُ أَنَسًا، قَالَ ذُكِرَ لِي أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ لِمُعَاذٍ ‏"‏ مَنْ لَقِيَ اللَّهَ لاَ يُشْرِكُ بِهِ شَيْئًا دَخَلَ الْجَنَّةَ ‏"‏‏.‏ قَالَ أَلاَ أُبَشِّرُ النَّاسَ قَالَ ‏"‏ لاَ، إِنِّي أَخَافُ أَنْ يَتَّكِلُوا ‏"‏‏.‏
Reference : Sahih al-Bukhari 129
In-book reference : Book 3, Hadith 71
USC-MSA web (English) reference : Vol. 1, Book 3, Hadith 131
  (deprecated numbering scheme)