Historical Rules · 17 June 2011
Rule 602.5a
Official source text from the 17 June 2011 Rules release
A creature's activated ability with the tap symbol ({T}) or the untap symbol ({Q}) in its activation cost can't be activated unless the creature has been under its controller's control since the start of his or her most recent turn. Ignore this rule for creatures with haste (see rule 702.10).