397. Reply of the perents
بَارَكَ اللَّهُ لَكَ، وَبَارَكَ عَلَيْكَ، وَجَزَاكَ اللَّهُ خَيْرًا، وَرَزَقَكَ اللَّهُ مِثْلَهُ، وَأَجْزَلَ ثَوَابَكَ
Baarakallahu laka wa baaraka 'alayka, wa jazaakAllahu khayran, wa razaqakAllahu mithlahu, wa 'ajzala thawaabaka
Translation
May Allah bless you, and shower His blessings upon you, and may Allah reward you well and bestow upon you its like and reward you abundantly.
The above congratulations and answer are narrated from some of the Companions.
ReferenceAn-Nawawi Al-Azkar Page. 349. Also see Sahih Azkar fil Nawawi, Salim al Hilali 2/713. For more details, read Az Zikr wa dua Wal Ilaj bir Ruqwa Page. 1/416