Merit (puñña) refers to purifying ... - Dhamma by Ajahn Jayasāro
Merit (puñña) refers to purifying acts of body, speech and mind. Merit is created by giving, by keeping precepts and by spiritual cultivation. In Buddhist cultures most emphasis has usually been placed on the first of these three.
But on one occasion the Buddha said that even as the radiance of all the stars in the sky does not equal one small part of the moon's radiance, so the liberation of the mind by loving-kindness surpasses all other meritorious activities and ‘shines forth, bright and brilliant’
Source: