1 Samuel 20:7

If he say thus, It is well; thy servant shall have peace: but if he be very wroth, then be sure that evil is determined by him.

Cross-reference

In 1 Samuel 20:9, Jonathan assures David he would tell him if harm were determined — directly responding to the test proposed here.

In 1 Samuel 20:32, Jonathan defends David, confirming the danger Saul's anger foretold in this verse.

Esther 7:7 Parallel

In Esther 7:7, the king's anger signals Haman's doom — parallel to how Saul's anger here signals David's danger.