Nahj al-Balāgha

Hadith 2114
generositycertainty
١٣٨. وَقَالَ (عليه ‏السلام): مَنْ أَيْقَنَ بِالْخَلَفِ جَادَ بِالْعَطِيَّةِ.
138. Amīr al-mu’minīn, peace be upon him, said: He who is sure of a good return is generous in giving.
Source: al-Sharīf al-Raḍī