Sahih al-Bukhari 706
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · The shortening and perfection of the prayer (by the Imam)
Narrated Anas:
حَدَّثَنَا أَبُو مَعْمَرٍ ، قَالَ حَدَّثَنَا عَبْدُ الْوَارِثِ ، قَالَ حَدَّثَنَا عَبْدُ الْعَزِيزِ ، عَنْ أَنَسٍ ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يُوجِزُ الصَّلاَةَ وَيُكْمِلُهَا.
The Prophet (ﷺ) used to pray a short prayer (in congregation) but used to offer it in a perfect manner.