Supplication for someone who spends his wealth

بَارَكَ اللّٰهُ لَكَ فِيْ اَهْلِكَ وَمَالِكَ

May Allah bless you in your family and your wealth.

1. Sahih al-Bukhari, no. (2049), Sunan at-Tirmidhi, no. (1933), Sunan an-Nasa'i, no. (3388).