Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that whenever the Prophet (peace and blessings be upon him) congratulated a person who had married, he would say: 'Barakallahu laka, wa baraka 'alayka, wa jama'a baynakuma fi khayr' (May Allah bless you, and send blessing upon you, and bring the two of you together in goodness).
(b) In the narration of al-Muqri' it says: When a man married, the Prophet (peace and blessings be upon him) would congratulate him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13841