1 Samuel 13:8

“And you shall go down before me to Gilgal; and behold, I will come down to you to offer burnt offerings and sacrifice peace offerings. You shall wait seven days until I come to you and make you know what you should do.”

So Amasa went to call out the men of Judah, but he delayed longer than the set time which he had appointed him.

Now the sons of Israel were mustered and were provided for and went to meet them; and the sons of Israel camped before them like two little flocks of goats, but the Arameans filled the land.

Saul Doesn’t Keep Yahweh’s Commandment