Man tha allathee yuqridu Allaha qardan hasanan fayudaAAifahu lahu walahu ajrun kareem (surah Hadid: 11)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(57:11) Who is it that will give Allah a beautiful loan? A loan that Allah will repay after increasing it many times and grant him a generous reward. *16

man zal lazee yuqridul laaha qardan hasanan fa yudaa`ifahoo lahoo wa lahooo ajrun kareem

*16) How Generous and Beneficent is Allah that if a man spends the wealth granted by Himself in His way, He calls it a loan Himself, provided that it is a good loan, that is, a loan which in given with a pure intention, without any selfish motive of winning reputation and renown, or of doing favour to somebody, but only for the sake of Allah's approval and to win His good-will and rewards. Allah makes two promises in this regard: (1) That He will repay it increasing it manifold; and (2) that He will also give from Himself the best reward for it.
According to a Hadith reported by Hadrat `Abdullah bin Mas'ud, when this verse was revealed and the people heard it from the Holy Prophet (upon whom be Allah's peace), Hadrat Abud-Dahdah Ansari asked: "O Messenger of Allah, dces Allah want a loan from us? The Holy Prophet replied: Yes, O Abud-Dahdah,. He said Kindly show me your hand. The Holy Prophet extended his hand towards him. He took his hand in his own hand and said: I give away my garden in loan to my Lord." Hadrat 'Abdullah bin Mas'ud says that the garden had 600 date-palms and his own house also in which his family lived- Saying this to the Holy Prophet (upon whom be Allah's peace) he went straight back home, and calling out to his wife said: "Come out, O mother of Dahdah, I have loaned this garden to my Lord." She replied: "Dahdah's father, you have made a, good bargain !' and she immediately vacated and left the garden with her effects and children." (Ibn Abi Hatim). This incident throws light on the conduct of the sincere believers of that time, and from this one can also understand the kind of the "good loan" that Allah has promised to return increasing it manifold with a rich reward in addition.