Abu Huraira (Radhiya-allahu-'anhu) narrates that the Prophet (ﷺ) said:
"Whoever gives in charity the value of a date from lawful earnings and Allah accepts only what is lawful — Allah will take it in His Right Hand and nurture it for its giver, just as one of you nurtures his colt, until it becomes like a mountain." — (Saheeh al-Bukhari)