leqaḥ

This word is built straight off the everyday Hebrew verb "to take" (לָקַח), and that is the key to it. Teaching is named here from the receiving end. It is the thing that gets taken. Where English "teaching" points at what the teacher does, this word points at what lands in the hearer.

That one idea faces two directions, and Hebrew is happy to let it face both:

• from the teacher's side it is the content handed over, as when Moses calls his closing song his teaching and asks that it soak in like rain on grass
• from the learner's side it is the growing stock of understanding a person builds up, which is why the wise are told to keep adding to it

Because the word is about what someone takes in, it carries a quiet expectation with it: instruction nobody receives is not yet doing its work. Proverbs keeps pairing the word with the verb "to add", and the point is never that more was said, only that more went in.

The same idea of taking turns outward here. If teaching is what a hearer takes in, this is the property of speech that gets itself taken: its grip, its winning force. Hebrew has no separate word for that, so it reuses this one.

Proverbs puts the idea to work on both sides of the moral line. In one warning scene a woman's steady flow of smooth talk simply carries a young man off, and the point is not the content of what she said but that it worked. In two later sayings the same quality belongs to the wise: pleasant speech and a thoughtful heart make what a person says land, so that good sense actually gets a hearing.

This is the harder half of the word, and translators split over it. Where one English Bible reads "learning" or "instruction" in the two Proverbs 16 sayings, another reads "persuasiveness", because the Hebrew can honestly bear either. The sayings make sense both ways: sweet speech makes teaching go further, or sweet speech makes a speaker convincing.