Albert Barnes Commentary Zechariah 7:10

"and oppress not the widow, nor the fatherless, the sojourner, nor the poor; and let none of you devise evil against his brother in your heart." — Zechariah 7:10 (ASV)

And oppress not - He had commanded positive acts of love; he now forbids every sort of unlove. He that oppresseth the poor, Solomon had said, reproacheth his Maker. The widow, the orphan, the stranger, the afflicted (Proverbs 24:31), are, throughout the law, the special objects of God’s care.

This was the condition which God made by Jeremiah; If ye thoroughly amend your ways and your doings, if ye thoroughly execute judgment between a man and his neighbor; if ye oppress not the stranger the fatherless and the widow, and shed not innocent blood in this place, neither walk after other gods to your hurt, then will I cause you to dwell in this place (Jeremiah 7:5–7). It was on the breach of the covenant to set their brethren free in the year of release, that God said; I proclaim a liberty for you to the sword, to the pestilence and to the famine, and I will make you to be removed into all the kingdoms of the earth (Jeremiah 34:17).

And let none of you imagine - that is, devise, as, by Micah, God retorted the evil upon them. They devised evil on their beds; therefore, behold, against this family do I devise an evil, from which ye shall not remove your necks (Micah 2:1, Micah 2:3).