Send to Sleep is a common Instant card from Magic Origins (ORI), collector number 71. Current market price: $0.07 (foil $0.26), TCGplayer market prices via Scryfall.
Tap up to two target creatures. Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, those creatures don't untap during their controllers' next untap steps.