Comprehensive Rules
702.103a
Bestow represents a static ability that functions in any zone from which you could play the card itâs on. âBestow [cost]â means âAs you cast this spell, you may choose to cast it bestowed. If you do, you pay [cost] rather than its mana cost.â Casting a spell using its bestow ability follows the rules for paying alternative costs (see 601.2b and 601.2fâh).