Albert Barnes Commentary Zechariah 7:9

"Thus hath Jehovah of hosts spoken, saying, Execute true judgment, and show kindness and compassion every man to his brother;" — Zechariah 7:9 (ASV)

Thus spoke the Lord – that is, through the former prophets, for he goes on to speak of their rejection in the past. Execute true judgment. He retains the words of Ezekiel. The injunction itself runs throughout the prophets. Show mercy (as in Isaiah 1:17, Isaiah 1:23; Isaiah 58:6–7; Jeremiah 7:5; Ezekiel 18:8; Hosea 12:6, etc.), that is, tender love to all, compassion to the unhappy.

Omit no act of love. God so loves the loving.

Lapide: “Like Paul to the Romans (Romans 13:9), he names only the duties to the neighbor, but understands what relates to God. For the love of our neighbor presupposes the love of God, from which it springs.”

Jerome: “After strictness of justice, let mercy to all follow, and especially to brothers, of the same blood and of one faith. We ought to consider the whole human race as brother and neighbor, since we are all born of one parent, or are those who are of the household of faith, according to the parable of the Gospel, “which wills us to understand by ‘neighbor’ not our relatives, but all people” (Luke 10:30 and following).”