A.T. Robertson Commentary Matthew 12:7

"But if ye had known what this meaneth, I desire mercy, and not sacrifice, ye would not have condemned the guiltless." — Matthew 12:7 (ASV)

The guiltless (τους αναιτιους). So in verse 5. Common in ancient Greek. No real ground against, it means αν + αιτιος. Jesus quotes Ho 6:6 here as he did in Mt 9:13. A pertinent prophecy that had escaped the notice of the sticklers for ceremonial literalness and the letter of the law.