“Judah and Israel were as many as the sand that is by the sea in abundance.” God made good on his promise to Abraham and Jacob about how numerous their descendants would be (Gen. 22:17; 32:12).
“eating and drinking and rejoicing.” Here in 1 Kings 4:20, “ate and drank” is used idiomatically as a kind of polarmerismos to express living life in general. The text could have said more literally, “the people lived their lives and were happy.” (Polarmerismos occurs when two extremes are used to represent a whole, such as in the southern expression, “that is the long and short of it,” meaning, “that is all there is.” We see the same figure in 1 Kings 3:7).
[See word study on “merismos.”]