Dua For Someone Who Lends You Money

بارَكَ اللهُ لَكَ في أَهْلِكَ وَمالِك، إِنَّما جَـزاءُ السَّلَفِ الْحَمْدُ والأَدَاء

May Allah bless you in your family and your wealth, surely the reward for a loan is praise and returning (what was borrowed).

Pronunciation: Baarakallaahu laka fee 'ahlika wa maalika, 'innamaa jazaa'us-salafil-hamdu wal'adaa'

Reference: Ibn Majah: 2424