Therefore, every one should renounce them. These three should never be forsaken even in imminent danger, viz., a follower, one who seeks protection, saying,—I am thine,—and lastly one who hath come to your abode. Verily, O Bharata, liberating a foe from distress, alone amounteth in point of merit, to these three taken together, viz., conferring a boon, acquiring a kingdom, and obtaining a son.

In plain words: Vidura says bad things should be given up. Three should never be abandoned even in danger: a loyal follower, someone who comes saying 'I am yours, protect me,' and a guest in your home. Freeing even an enemy from trouble earns as much merit as granting a wish, gaining a kingdom, and having a son, all together.