Sunan an Nasai 822
The Book of Leading the Prayer (Al-Imamah)
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ مِسْعَرٍ، عَنْ ثَابِتِ بْنِ عُبَيْدٍ، عَنِ ابْنِ الْبَرَاءِ، عَنِ الْبَرَاءِ، قَالَ كُنَّا إِذَا صَلَّيْنَا خَلْفَ رَسُولِ اللَّهِ صلى الله عليه وسلم أَحْبَبْتُ أَنْ أَكُونَ عَنْ يَمِينِهِ .
It was narrated that Al Bara said:"When we prayed behind the Messenger of Allah (ﷺ) I liked to be to his right
Grading: Abu Ghuddah: Sahih · Al-Albani: Sahih · Zubair Ali Zai: Sahih Muslim
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.