a honeycomb, and the fresh honey running out of it, held up in poetry as the measure of sweetness
This word appears only twice, and both times it is a yardstick. In Psalm 19:10 the Lord's rulings are called sweeter than honey and than what drips from the combs. In Proverbs 16:24 kind words are called a honeycomb, sweet to the soul and healing to the bones. In each place something else is being praised, and this word is the standard it is measured against.
It is not the everyday word for honey (דְּבַשׁ), which covers honey as food, as a gift, and in the promise of a land flowing with milk and honey. This is the poetic word, and it points at honey in its best state: still in the wax, or running fresh out of it. That is why Psalm 19 can name honey and then name this and still be raising the bar. The word standing beside it there (נֹפֶת) is honey that runs out of the comb on its own, so the two together describe the choicest grade there is.
Honey in ancient Israel was not only something stumbled on in a rock crevice. Archaeologists working in the Jordan Valley have uncovered rows of clay hives from roughly the tenth century BC, dozens of them, capable of yielding several hundred pounds of honey a year. When a poet reached for this picture, readers knew what fresh comb honey was worth.
A verb spelled with the same letters (צוּף) means to flow over or to float, and the older lexicons explained the noun from it: a comb is the thing honey flows out of. It is a reasonable guess and may well be right, but it has never been shown, and neither of these two verses turns on it.