Deuteronomy 25:5 speaks of an obligation to marry your brothers wife and conceive a child there is no mention of “spilling seed”. Which leads me back to God was angry Onan disobeyed his will not because he ejaculated outside the wife. None of which leads to unproductive ejaculation as a reason he was struck down. Maybe I’ve missed something.
See post 228. The Protestant reformers understood what I’m saying quite clearly.