John Gill Commentary Jeremiah 34:13

"Thus saith Jehovah, the God of Israel: I made a covenant with your fathers in the day that I brought them forth out of the land of Egypt, out of the house of bondage, saying," — Jeremiah 34:13 (ASV)

Thus says the Lord, the God of Israel The covenant God of Israel, their Creator, Redeemer, and Benefactor:

I made a covenant with your fathers; gave them a system of laws, among which was that of release of servants:

in the day that I brought them forth out of the land of Egypt; that is, at that time, quickly after, when they were come to Mount Sinai. This shows what fathers are meant: the Jewish ancestors that came out of Egypt, brought from thence by the mighty hand of God, and indulged with many favours by him, both in the wilderness, and in the land of Canaan, where he brought and settled them:

out of the house of bondmen; where they were bondmen, servants, and slaves. This is mentioned to put them in mind of their former state and condition; to observe to them the foundation and ground of the law concerning servants, how equitable and merciful it was, and to aggravate their sin. Though their fathers had been bondmen, and they must have been so too had they not been released, yet they acted such a cruel part to their servants, who were their brethren, in not discharging them in due time:

saying; giving out the following law, as a part of the covenant made with their fathers.