And whatever you give for interest [i.e., advantage] to increase within the wealth of people1 will not increase with Allāh. But what you give in zakāh,2 desiring the face [i.e., approval] of Allāh - those are the multipliers.3
Translation: Saheeh International (English)
1 The phrase includes several connotations, among them: a) that which is given as usury or interest, b) that which is given on the condition that it be repaid with interest, and c) a gift given with the intention of obtaining from the recipient greater benefit or a larger gift.
2 The meaning of ṣadaqah (voluntary charity) is included here.
3 Of their blessings on earth and their rewards in the Hereafter.
Whatever wealth you give to anyone with the expectation that they will.return it to you with an increase, that wealth does not grow with Allah. And whatever wealth you give to fulfil someone's need, desiring only the pleasure of Allah, and not praise or reward from the people, the reward of that deed shall be multiplied for you by Allah.