। ॥ ६२३ ॥
In plain words
Since the Self is happiness by its very nature, ānanda is its own defining mark, not a quality lent to it from outside. And the Self is happiness by nature because it is the one thing loved above all else — the place where the highest love comes to rest.
Close to the Sanskrit
Because of the Self's being of the nature of happiness, blissfulness is its own defining mark; through its being the resting-place of the highest love, the Self's being of the nature of happiness is established.