Reference : Hisn al-Muslim 39

رَبَّنـا وَلَكَ الحَمْـدُ
حَمْـداً كَثـيراً طَيِّـباً مُـبارَكاً فيه
Rabbanā wa lakal-ḥamd, 
ḥamdan kathīran ṭayyiban mubārakan fīh.

Our Lord, praise is Yours, 
abundant, good and blessed praise.

Reference:
Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 2/284.

Chapter: Upon rising from the bowing position