Abu Umama told of Abu Dharr asking God’s Prophet (ﷺ) to tell him what the reward for <i>sadaqa</i> would be, and receiving the reply, “Many times as much, and more still with God.” Ahmad transmitted it.

وَعَنْ أَبِي أُمَامَةَ قَالَ: قَالَ أَبُو ذَرٍّ: يَا نَبِيَّ اللَّهِ أَرَأَيْتَ الصَّدَقَةُ مَاذَا هِيَ؟ قَالَ: «أَضْعَافٌ مُضَاعَفَةٌ وَعِنْدَ اللَّهِ الْمَزِيدُ» . رَوَاهُ أَحْمد