A.T. Robertson Commentary Matthew 21:41

"They say unto him, He will miserably destroy those miserable men, and will let out the vineyard unto other husbandmen, who shall render him the fruits in their seasons." — Matthew 21:41 (ASV)

He will miserably destroy those miserable men (κακους κακως απολεσε αυτους). The paronomasia or assonance is very clear. A common idiom in literary Greek. "He will put the wretches to a wretched death" (Weymouth).

Which (οιτινες). Who, which very ones of a different character.