Historical Rules · 10 August 2018
Rule 615.8
Official source text from the 10 August 2018 Rules release
Some prevention effects generated by the resolution of a spell or ability refer to the next time a specific source would deal damage. These effects prevent the next instance of damage from that source, regardless of how much damage that is. Once an instance of damage from that source has been prevented, any subsequent instances of damage that would be dealt by that source are dealt normally.