Jeremiah 34:18

“And I will give the men that have transgressed my covenant, etc.] The covenant the king, princes, and all the people made, to let their servants go free, is called the Lord’s covenant, because made in his name, in his presence, and before him as a witness; and very probably the calf that was cut in pieces on this occasion, after mentioned, was sacrificed to him, which made him a party concerned; unless this is to be understood of the covenant of God in general made with Israel on Mount Sinai; and so is distinct from the other covenant, which may be more especially designed in the next clause: which have not performed the words of the covenant made before me; did not perform what they…”

“passed between the parts thereof--The contracting parties in the "covenant" (not here the law in general, but their covenant made before God in His house to emancipate their slaves, Jer 34:8-9) passed through the parts of the animal cut in two, implying that they prayed so to be cut in sunder (Mat 24:51; Greek, "cut in two") if they should break the covenant (Gen 15:10, Gen 15:17).”

“It is usual with commentators to say that, the laws dealing with the emancipation of the Hebrew slaves, as also that of the land resting during the sabbatical year, were not observed. The narrative teaches us the exact contrary. The manumission of the slaves on the present occasion was the spontaneous act of Zedekiah and the people. They knew of the law, and acknowledged its obligation. The observance of it was, no doubt, lax: the majority let their own selfish interests prevail; but the minority made might give way to right, and Zedekiah supported their efforts though only in a weak way. Early in January, in the ninth year of Zedekiah, the Chaldaean army approached Jerusalem. The people…”

“Cut the calf - It seems these Jews in their making of the solemn covenant with God about releasing their servants used this rite; they caused a calf, or heifer to be cut in pieces, and the parts to be laid in the temple, right over - against one another; then they recited this covenant, and passed between the parts of the heifer so cut; silently agreeing that God should cut them in pieces like that beast if they did not make their words good. Jeremiah 34:22”

“have transgressed: Deu 17:2; Jos 7:11, Jos 23:16; Hos 6:7, Hos 8:1 when: This was the ancient mode of making a covenant. (See note on Deu 29:12, and see note on Jos 9:7.) Gen 15:10, Gen 15:17, Gen 15:18; Psa 50:1 Jeremiah 34:19”