The season's second episode features appearances from both David's son Ty and his father-in-law Peter Davison, with the latter play biblical figure Job and the former playing his son Ennon.
However, David has revealed that he didn't find out about Ty's casting until after the fact, when he was shooting on the new season.
Speaking with Variety, David said: "I don't know how that happened. I do a bunch of self-tapes with Ty, but I don't think I did this one with him because I was out of town filming Good Omens. He certainly wasn't cast before we started shooting. There were two moments during filming where Neil [Gaiman] bowled up to me and said, 'Guess, who we've cast?'"
David continued: "Ty definitely auditioned and, as I understand it, they would tell me, he was the best. I certainly imagine he could only possibly have been the best person for the job. He is really good in it, so I don't doubt that's true.
"And then my father-in-law showed up, as well, which was another delicious treat. In the same episode and the same family! It was pretty weird. I have worked with both of them on other projects, but never altogether."