[2] The expressions 'swarm over the earth' and so 'multiply in it' are used for the following reason: With a regenerate person nothing multiplies in his external man, that is, no good or truth at all is ever increased, unless it is the product of charity. Charity is like the warmth in springtime or summer that causes grass, plants, and trees to grow. Without charity, or spiritual warmth, nothing grows, and this is why the first expression used here is 'swarm over the earth' which has reference to goods that flow from charity, by means of which good and truth are multiplied. Anyone may grasp how this is so; nothing with a person grows and multiplies unless some affection is there. The delight that is part of the affection not only causes something to take root, but also causes it to grow. Everything depends on the influence of the affection.

[3] That which a person loves he freely takes in, retains, and treasures - and so everything that supports some affection. Those which do not support it he has no interest in, regards as worthless, in fact rejects. But the character of the affection determines that of the multiplication. With somebody who is regenerate it is an affection for good and truth deriving from charity given by the Lord. Consequently whatever supports an affection deriving from charity he takes in, retains, and treasures, and so strengthens himself in goods and truths. This is what is meant by 'swarm over the earth and multiply'.