It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever, having power over a trust from the wealth of this world, hands it over (to its rightful owner) when he could have withheld it if he wished, Allah, the Mighty and Majestic, will marry him to the wide-eyed maidens of Paradise (hur al-'in) wherever he wishes."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7896