Why does Les go back to Hebrews 11 after telling the account of the midwives?
He returns to Hebrews 11 so the midwives' actions are understood through Scripture rather than dismissed as a mere story. Unless God's Word is comprehended regarding what these people did, it goes in one ear and out the other; the account carries deeper spiritual significance than a bare narrative.
Les explains that he goes back to Hebrews 11 because, unless we comprehend what God's Word says about the activities of these people, it probably just goes in one ear and out the other. He adds that there is more to it than that, and that this is not just a story. The context concerns the midwives who feared God and did not do as the king of Egypt commanded them, but saved the men's children alive.