Historical Rules · 3 February 2023
Rule 119.9
Official source text from the 3 February 2023 Rules release
Some triggered abilities are written, “Whenever [a player] gains life, . . . .” Such abilities are treated as though they are written, “Whenever a source causes [a player] to gain life, . . . .” If a player gains 0 life, no life gain event has occurred, and these abilities won’t trigger.