Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: Whoever gives a gift for the sake of Allah, then that is his; and whoever gives a gift wanting a return for it, he may take it back if he is not satisfied (with the return).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الهبات / 12023