Historical Rules · 1 February 2013
Rule 702.95a
Official source text from the 1 February 2013 Rules release
Scavenge is an activated ability that functions only while the card with scavenge is in a graveyard. "Scavenge [cost]" means "[Cost], Exile this card from your graveyard: Put a number of +1/+1 counters equal to the power of the card you exiled on target creature. Activate this ability only any time you could cast a sorcery."