(Al Hadeed) 57 : 18
إِنَّ الْمُصَّدِّقِينَ وَالْمُصَّدِّقَاتِ وَأَقْرَضُوا اللَّهَ قَرْضًا حَسَنًا يُضَاعَفُ لَهُمْ وَلَهُمْ أَجْرٌ كَرِيمٌ
Indeed, the men testifying to the Truth and the women testifying to the Truth, and those who are lending the best loan to Allah, it will be increased for them in manifold, and for them is a noble reward.
See explanation 33: 35; 49: 15; 57: 11; and 61: 14.