כֹּ֥ה אָמַ֖ר יְהוָ֣ה אֱלֹהָ֑י רְעֵ֖ה אֶת־צֹ֥אן הַהֲרֵגָֽה׃
Thus said the LORD my God: ‘Feed the flock of slaughter;
Rashi on Zechariah
Tend the flock of slaughter Prepare shepherds for them; i.e., prophesy concerning their leaders who are destined to lead them from now on.
Rashi on Zechariah
the flock of slaughter Israel, whose shepherds slew them and devoured them.