Historical Rules · 1 October 2009
Rule 405.6c
Official source text from the 1 October 2009 Rules release
Mana abilities resolve immediately. If a mana ability produces both mana and another effect, both the mana and the other effect happen immediately. If a player had priority before a mana ability was activated, that player gets priority after it resolves. (See rule 605, "Mana Abilities.")