Sunan Ibn Majah, Volume 3, Book 9, Hadith 1905 (DarusSalam) ⓘ
It was narrated from Abu Hurairah: that the Prophet used to say, when offering congratulations of the occasion of marriage: “Barak Allahu lakum, wa barak 'alaikum, wa jama'a bainakuma fi khair (May Allah bless you and bestow blessings upon you, and bring you together in harmony).”
حَدَّثَنَا سُوَيْدُ بْنُ سَعِيدٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ الدَّرَاوَرْدِيُّ، عَنْ سُهَيْلِ بْنِ أَبِي صَالِحٍ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ كَانَ إِذَا رَفَّأَ قَالَ " بَارَكَ اللَّهُ لَكُمْ وَبَارَكَ عَلَيْكُمْ وَجَمَعَ بَيْنَكُمَا فِي خَيْرٍ " .
also referenced under: Hadith 1905 (Reference) & Book 9, Hadith 1980 (In-Book)