Hadith 1216 - Actions while Praying - Sahih Al-Bukhari - صحيح البخاري - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

21. Actions while Praying - كتاب العمل فى الصلاة

15) Chapter: One should not retune greetings during the Salat

Narrated `Abdullah:

I used to greet the Prophet (ﷺ) while he was in prayer and he would return my greeting, but when we returned (from Ethiopia) I greeted the Prophet (ﷺ) (while he was praying) but he did not return the greeting, and (after finishing the prayer) he said, "In the prayer one is occupied (with a more serious matter)."

Reference: 1216
English reference: Vol. 2, Book 22, Hadith 307
In-book reference: Book 21, Hadith 20
Grade: Sahih
Read this hadith from Darussalam Collection

15) باب لاَ يَرُدُّ السَّلاَمَ فِي الصَّلاَةِ

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا ابْنُ فُضَيْلٍ، عَنِ الأَعْمَشِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ، قَالَ كُنْتُ أُسَلِّمُ عَلَى النَّبِيِّ صلى الله عليه وسلم وَهُوَ فِي الصَّلاَةِ فَيَرُدُّ عَلَىَّ، فَلَمَّا رَجَعْنَا سَلَّمْتُ عَلَيْهِ فَلَمْ يَرُدَّ عَلَىَّ وَقَالَ ‏‏‏.‏ "‏ إِنَّ فِي الصَّلاَةِ شُغْلاً ‏"