Aisha reported: The Messenger of Allah, peace and blessings be upon him, said:

Verily, Allah is kind and he loves kindness. He rewards for kindness what is not granted for harshness and he does not reward anything else like it.

إِنَّ اللَّهَ رَفِيقٌ يُحِبُّ الرِّفْقَ وَيُعْطِي عَلَى الرِّفْقِ مَا لَا يُعْطِي عَلَى الْعُنْفِ وَمَا لَا يُعْطِي عَلَى مَا سِوَاهُ

Source: Ṣaḥīḥ Muslim 2593, Grade: Sahih