‘From Insights from Filmmaking for Analyzing Biblical Narrative:
A more prominent issue in the scholarly debate on this verse relates to the words of the angel of the Lord, “now I know …. ” On this phraseology, john Walton summarizes the key issue in the debate when he writes, “interpreters … object that God, in his omniscience, must have known that Abraham would do what he did. God, by his nature and affirmed attributes, cannot add to his cognitive knowledge.” On this issue, Walton himself suggests, “We must differentiate between knowledge as cognition and knowledge as experience. We can agree that God knew ahead of time what Abraham was going to do. But there is ample evidence throughout Scripture that God desires us to act out our faith and worship regardless of the fact that he knows our hearts.”36 Gunkel, on the other hand, addresses the apparent challenge to God’s omniscience in this verse by explaining, “The use of this concept in reference to God implies an anthropomorphism because, strictly taken, it excludes omniscience,” suggesting that this attribution of a lack of omniscience to God was simply due to inadvertence on the part of the author ofE in his crafting37 of this account. Note how both these authors work to explain how this text could possibly suggest that God is here coming to know something new, a dynamic not in keeping with the idea that God is omniscient. In other words, both authors take God’s omniscience as a given. In the world of systematic theology, this is certainly a trait that has been attributed to God. It must be noted, however, that this attribution has emerged out of theological study of the Bible as a whole, and not from this narrative itself. Once again, this is at odds with a cinematic-story paradigm in which any given text is part of a self-contained storyworld (seep. 40, above). Therefore, analysis of the omniscience of God in Gen 22:12 ought to consider evidence only from the story-world of the Pentateuch on this issue. Further, the sequentiality of all stories (seep. 53, above) means that only evidence found in the text preceding Gen 22:12 should be considered, as subsequent evidence is not yet within the purview of a reader coming upon this verse.'
source: Gary Yamasaki on Reading Biblical Stories (godisopen).