Historical Rules · 5 October 2018
Rule 701.14b
Official source text from the 5 October 2018 Rules release
If the effect of a static ability regenerates a permanent, it replaces destruction with an alternate effect each time that permanent would be destroyed. In this case, “Regenerate [permanent]” means “Instead remove all damage marked on [permanent] and tap it. If it’s an attacking or blocking creature, remove it from combat.”