Commentaries:
God uses this principle in His judgments—greater and lesser punishments for greater and lesser sins. Under "an eye for an eye" in the Bible, the punishment must match, but not exceed, the damage or harm done by the perpetrator. The law placed strict limits on the amount of damages anyone could collect. It permitted no one to "get rich quick" from another's mishap. Moreover, God intended this law to be a rule of thumb for judges, not an authorization of personal vendetta or private retaliation.
Martin G. Collins
Are Some Sins Worse Than Others?
To whom does the "lasting harm" refer, the mother, the fetus, or both? If it refers to the fetus or both, then the Word of God recognizes the personhood of the fetus. Regardless of its age, if the fetus dies as a result of the fight, its death becomes a capital crime, just as punishable as if the mother had been killed.
John W. Ritenbaugh
Murder?
Without doubt, death is "lasting harm." These verses illustrate the accidental miscarriage of the unborn. If the miscarried baby dies, although no harm was intended against it, the judgment is manslaughter, and the accused can become a victim of the avenger of blood (Genesis 9:6; Numbers 35:9-34; Deuteronomy 19:4-13; Joshua 20). How much more valid is the judgment of murder if the unborn is the intended victim? The Bible shows that the unborn "unviable tissue mass" is human. God's viewpoint is clear: Willful killing of the unborn—abortion—is murder.
John W. Ritenbaugh
Abortion: The Land Is Full of Bloody Crimes
Other Forerunner Commentary entries containing Exodus 21:23:
Exodus 20:14
Obadiah 1:15-16
Matthew 5:38-40
Matthew 5:38-39