“And it came to pass after these things, that God did tempt Abraham, and said unto him, Abraham: and he said, Behold, here I am.”
After these things God tests Abraham. The narrator announces the nature of the event before it unfolds — this is a test. God calls to Abraham and he answers with hineni: here I am. The simple, present, attentive answer is the characteristic response of the fully available servant — Isaiah 6:8, Samuel in 1 Samuel 3:4, Moses in Exodus 3:4. Hebrews 11:17 interprets what follows as the apex of Abraham's faith. The application: the test comes after the covenant life has been established, after the promises have been tasted. The hardest tests tend to come after the greatest blessings.