How can God be omniscient if He did not know what Israel would do

God “tests” us, not for His sake, but for ours. For example, Ecc. 3:18 tells us, “God tests them, that they may see that they themselves are like animals…” In school, students are given periodic tests to show them their current progress—what they think they know but don’t, where they are wrong and need to relearn—so they can have a “course correction” before it is too late. After seeing God’s miraculous provision, both Abraham and the children of Israel were “tested” to see if they had learned the lesson that they could trust God (Gen. 22:1; Exod. 15:25). God brings tests and trials to those He loves, to cause them to mature and develop godly character. Tribulation, temptation, and persecution “establish, strengthen, and settle” the godly (see 1 Pet. 5:10). See also Psa. 66:10–12.

Judges 3:4 And they were left, that He might test Israel by them, to know whether they would obey the commandments of the Lord, which He had commanded their fathers by the hand of Moses.