A thing is lost if cast into the sea; words are lost if addressed to one that listens not; the scriptures are lost on one that hath not his soul under control; and a libation of clarified butter is lost if poured over the ashes left by a fire that is extinguished. He that is endued with the intelligence maketh friendships with those that are wise, having first examined by the aid of his intelligence, repeatedly searching by his understanding, and using his ears, eyes, and judgment.

In plain words: Some things are simply wasted: something dropped in the sea, words said to someone who won't listen, holy teachings given to someone with no self-control, and butter offered into a dead fire. A wise person picks friends carefully, watching, listening, and judging them again and again before trusting them.