Determined Iteration is a rare Enchantment card from Secrets of Strixhaven Commander (SOC), collector number 122. Current market price: $0.37, TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, populate. The token created this way gains haste. Sacrifice it at the beginning of the next end step. (To populate, create a token that's a copy of a creature token you control.)