The proverb means that performing a good deed, no matter how small, will always have a positive impact, even if it may not be immediately obvious. It implies that even seemingly insignificant acts of kindness or generosity can have a lasting impact, and that no good deed ever goes unnoticed or unrewarded.
The proverb is believed to have originated from the writings of the 4th-century theologian and bishop Saint Basil of Caesarea. In his homilies, he wrote:
A good deed is never lost; he who sows courtesy reaps friendship, and he who plants kindness gathers love.