“Be merciful, even as your Father is merciful”
Be merciful, just as your Father is merciful. (Luke 6:36 BSB)
What it sounds like today
A different saying from Matthew's 'be perfect.'
The cultural key
Same position in the sermon, same function, different key word: where Matthew concludes the enemy-love teaching with 'you therefore must be perfect (teleios), as your heavenly Father is perfect,' Luke has 'merciful.' Luke's wording works as a translation of Matthew's: teleios renders the Hebrew idea of wholeness, and the wholeness in question is love without gaps, proven on enemies. Luke states plainly what Matthew's idiom compresses. There is also a rabbinic-style echo: 'as he is compassionate, so you be compassionate.'
Recovered meaning
Luke is the built-in commentary on Matthew's most misread verse: the 'perfection' demanded is not flawlessness but mercy with no one left outside it. Where readers stumble on 'be perfect,' Luke hands them the intended sense.