SCRIPTURAL PRINCIPLES

Commentary - Exodus 22:2-3

John Calvin 

But although the details are not expressed with sufficient distinctness, still the intention of God is by no means ambiguous, viz., that if a thief should be killed in the dark, his slayer should be unpunished; for he can then hardly be distinguished from a robber, especially when he proceeds with violence; because he cannot enter another man's house by night without either digging through a wall or breaking down a door. The Twelve Tables differ slightly from this; for they permit the killing of a thief by night, and also by day if he should defend himself with a weapon. But, since God had sufficiently repressed by other laws murders and violent assaults, He is silent here respecting robbers who use the sword in their attempts at plunder. He therefore justly condemns to death those who have avenged by murder a theft in open day.  Biblehub.com

Ellicott's Commentary for English Readers

Rather, breaking in: i.e., making forcible entry into a dwelling-house. Most codes agree with the Mosaic in allowing the inmates of the house to resist such an attempt if made at night, and to shed the blood of the burglar, if necessary. He may be considered as having dissolved the “social compact,” and converted himself from a fellow-citizen into a public enemy. A murderous intent on his part may be suspected. Biblehub.com

Benson Commentary

If a thief broke into a house in the night, and was killed in the doing it, his blood was upon his own head; but if it were in the day-time that the thief was killed, he that killed him was accountable for it, unless it were in the necessary defence of his own life. Biblehub.com

Barnes' Notes on the Bible

If a thief, in breaking into a dwelling in the night, was slain, the person who slew him did not incur the guilt of blood; but if the same occurred in daylight, the slayer was guilty in accordance with Exodus 21:12Biblehub.com

Jamieson-Fausset-Brown Bible Commentary

A robber breaking into a house at midnight might, in self-defense, be slain with impunity; but if he was slain after sunrise, it would be considered murder, for it was not thought likely an assault would then be made upon the lives of the occupants. Biblehub.com

Matthew Poole's Commentary
For him, i.e. for the thief, though he be killed by a man in his own defence. Because in that case the thief might be presumed to have a worse design, and the owner of the house could neither expect or have the help of others to secure him from the intended violence, nor guide his blows with that discretion and moderation which in the day-time he might use. Biblehub.com

Gill's Exposition of the Entire Bible

If a thief be found breaking up...and be smitten that he die be knocked down with a club, by the master of the house, or any of his servants, or be run through with a sword, or be struck with any other weapon, to hinder him from entrance and carrying off any of the goods of the house, and the blow be mortal: there shall no blood be shed for him: as for a man that is murdered; for to kill a man when breaking into a house, and, by all appearance, with an intention to commit murder, if resisted, in defence of a man's self, his life and property, was not to be reckoned murder, and so not punishable with death: or, "no blood" shall be "unto him"; shall be imputed to him, the man that kills the thief shall not be chargeable with his blood, or suffer for shedding it; because his own life was risked, and it being at such a time, could call none to his assistance, nor easily discern the person, nor could know well where and whom he struck. Biblehub.com

Cambridge Bible for Schools and Colleges

A thief caught breaking in by night may be killed without any guilt being incurred by his death, but not if the act take place by day. In the dark the householder would probably not be able to recognize the burglar, so as to bring him to justice, nor would he know whether he might not intend murder: a mortal blow, given in defence of his life and property, would therefore be excusable under the circumstances: but no such excuse could be made for it in the light of day. Biblehub.com

Pulpit Commentary

If a thief be found breaking up. Rather, "Breaking in" - i.e., making forcible entry into a house. The ordinary mode of "breaking in" seems to have been by a breach in the wall. Hence the word here used, which is derived from khathar, "to dig." There shall no blood be shed for him. Rather, "the blood-feud shall not lie upon him" - i.e., the avenger of blood shall not be entitled to proceed against his slayer. The principle here laid down has had the sanction of Solon, of the Roman law, and of the law of England. It rests upon the probability that those who break into a house by night bare a murderous intent, or at least have the design, if occasion arise, to commit murder. Biblehub.com