Messenger of Allah ﷺ said, "They say Al-Karm (the generous), and in fact Al-Karm is the heart of a believer."  

قَالَ رَسُولُ اللَّهِ ﷺ وَيَقُولُونَ الْكَرْمُ إِنَّمَا الْكَرْمُ قَلْبُ الْمُؤْمِنِ