John Gill Commentary 1 Kings 4:20

"Judah and Israel were many as the sand which is by the sea in multitude, eating and drinking and making merry." — 1 Kings 4:20 (ASV)

Judah and Israel [were] many, as the sand which [is] by the sea in multitude Being blessed with great fruitfulness in their families, and having no pestilential disease among them, nor wars to lessen their number, and so the promise to Abraham was fulfilled, (Genesis 22:17); and which was an emblem of Christ's spiritual subjects, especially in the latter day, whom Solomon was a type of, see (Hosea 1:10);

eating, and drinking, and making merry having a large increase of the fruits of the earth, and in no fear of any enemies; expressive of the spiritual joy of believers in the kingdom of Christ, and under the word and ordinances, (Song of Solomon 2:3Song of Solomon 2:4) (5:1) (Romans 5:2Romans 5:3Romans 5:11) (14:17) .