1 Samuel 14:42

And Saul said, Cast lots between me and Jonathan my son. And Jonathan was taken.

The verse stands within the account of Jonathan's attack on the Philistines and the deliverance of Israel that followed. In that setting Jonathan was chosen to act after Saul's presumptuous offering. Because of that offering Saul was not given the honor of defeating the Philistines. The casting of lots between Saul and Jonathan is left without explanation in that account.