Bible Oral Narrations with 7 year old

Just a few months ago, I began having my 7 year old son give oral narrations. We have been working through Aesop’s fables and he really does a great job. Last week, I had him give a narration after reading a story in Outdoor Secrets, with only doing a paragraph at a time. It was a little challenging, but I was amazed at how much this showed what he had comprehended (and what he hadn’t understood). This week, we started reading Geneses 1 (ESV) and I asked him to narrate. I could tell that he didn’t really understand what I said because he just started trying to repeat words or phrases that he remembered me reading (just repeating words like expanse, separate the heavens, etc with no understanding of what those sentences meant). I am wondering if asking a 7 yr old to narrate after Bible readings is too much? Or maybe I am expecting too much during narrations? I would love to hear your experience!