Cheapest priced copy (Avacyn Restored): $0.35 at Card Kingdom, near mint, their price list as of .
Sheltering Word 
Instant · Common · Avacyn Restored · #192
Target creature you control gains hexproof until end of turn. You gain life equal to that creature's toughness. (A creature with hexproof can't be the target of spells or abilities your opponents control.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $2.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Avacyn Restored | 192 | Common | $0.35 | $2.99 |
| The List | AVR-192 | Common | $0.35 | — |
One ruling from Wizards of the Coast
- 1 May 2012If a creature gains hexproof in response to a spell or ability controlled by an opponent that targets only it, that spell or ability doesn’t resolve for having an illegal target when it tries to resolve.