A follow up to my last comment. Jesus already speaks non-literally in this specific text when he claims the “sign of Jonah” would be the only sign he would give. John lists at least seven “signs”—this is Jesus in frustration saying, in essence, “Are you serious? How much more do you need?”

Was the veil being ripped from top to bottom a sign? The eclipse coinciding with his crucifixion—the way he died? (The centurion thought so); etc.