Historical Rules · 1 October 2009
Rule 301.7a
Official source text from the 1 October 2009 Rules release
An Equipment is cast and enters the battlefield just like any other artifact. An Equipment doesn't enter the battlefield attached to a creature. The equip keyword ability moves the Equipment onto a creature you control (see rule 702.6, "Equip"). Control of the creature matters only when the equip ability is activated and when it resolves. The creature to which the Equipment is to be moved must be able to be equipped by it. If it can't, the Equipment doesn't move.