Commentary for Numbers 35:16

ואם בכלי ברזל הכהו BUT IF HE SMOTE HIM WITH AN INSTRUMENT OF IRON — This is not speaking of one who kills inadvertently, who is mentioned near this (in the preceding verse), but of one who kills intentionally; and its purpose is to teach us that with whatever instrument one kills, it is necessary that it must have a size sufficient to cause death, because in the case of all of them (vv. 17, 18) it is said, אשר ימות “[an instrument] by which one may die”, the Hebrew of which we translate in the Targum by, “[an instrument] which is of such a size that one may die through it” — in the case of all, except in that of iron, because it is manifest and known to the Holy One, blessed be He, that iron kills whatever size it may be (however small it is), even a needle. Therefore the Torah does not assign a size to it by writing ,אשר ימות בה (Sifrei Bamidbar 160:3; Sanhedrin 76b). And if you say that Scripture is speaking of one who kills inadvertently, — but surely it says lower down, (v. 23) “Or with any stone, even though one may die by it, (even though it is large enough to kill him) seeing him not”, which certainly is by inadvertence. This proves as regards the cases mentioned before it, that Scripture is speaking of one who kills intentionally.

ואם בכלי ברזל הכהו וימות רוצח הוא, “If he had struck him with an iron implement and he died, he is a murderer.” The Torah legislated that if someone killed with a stone or a wooden implement the court will examine if the force used was sufficient to result in death under normal circumstances, i.e. if the victim were healthy. We know this from verse 17: “If he struck him with a hand-sized stone which is sufficiently large to cause death, or with a wooden implement.” These words mean that the court must weigh the relative strength of the blow according to the physique of who administered it and according to the implement employed to strike the victim with. When the blow was struck with an iron tool or weapon, the Torah does not apply such criteria but assumes that anyone who strikes a blow with such an instrument has murderous intentions. Iron instruments, even if as small as a needle are capable of causing death. (Compare Maimonides Hilchot Rotzeach Nefesh 3,1; 3,2, etc.)
If the killer pushed the victim so that he fell off the roof of a building and died, this is a situation covered by the words in verse 20: “if he pushed him out of hatred or hurled him from an ambush so that he died,” the killer is automatically assumed to have had murderous intent. If less lethal instruments caused the death of the victim the court has to assess if the blows inflicted were prompted by hostility. This is why the Torah wrote: “or he struck him in enmity with his hand.”

Of a size capable. כמיסת means “of a size.”

V. 16. ואם בכלי ברזל usw. Von Versen 16 — 21 folgen erst Bestimmungen über die Modalitäten, die den vorsätzlichen Mord zur gerichtlichen Ahndung qualifizieren. Außer den durch Zeugen und vorgängige Warnung, עדים והתראה (Kap. 15, 33) zu konstatierenden subjektiven Merkmalen des Bewusstseins und Vorsatzes, kommen noch die objektiven Umstände, die von dem Täter in Bewegung gesetzten oder zu seinem Zwecke benutzten tötenden Mittel in Betracht, ob sie zu dem erfolgten Tode in solchem Verhältnis stehen, dass nach menschlicher Schätzung der Tod als direkte Wirkung der Handlung des Täters zu beurteilen sei. Es ist dabei Größe, Stoff und Beschaffenheit des Werkzeugs, die dabei angewandte Kraft des Täters, die bedrohte und getroffene Stelle, die körperliche Konstitution des Getöteten etc. vom Gerichte in Erwägung zu ziehen, wie alle diese Erwägungen in unserem Texte angedeutet sind. Es werden die verschiedenen Stoffe עץ ,אבן ,ברזל genannt, bei אבן und עץ steht die Beifügung כלי עץ יד ,אבן יד :יד, d. h. ein zu handhabender Stein, ein zu handhabendes hölzernes Gerät, und ist damit sowohl eine hinreichende Größe vorausgesetzt, als auch auf Schätzung der Kraft hingewiesen, die das Mittel in Bewegung gesetzt. Bei ברזל fehlt diese Beifügung, weil nach Sanhedrin 76 b auch die kleinste Verwundung durch Eisen tötlich werden kann (siehe תוספו׳ daselbst). Darum steht auch beim Stein und dem hölzernen Geräte: אשר ימות בו, es müssen Mittel und Schlag solche gewesen sein, dass er dadurch hat sterben können, dass der erfolgte Tod darauf zurückgeführt werden kann, und endlich heißt es überall הכהו וימות, es muss nach sachkundiger Ansicht der Tod in Folge des Schlages eingetroffen sein; dann ist er ein רצח, ein "Mörder", und מות יומת הרצח, und es ist sein Tod durch Menschenhand zu bewirken.

The murderer must be executed. Here it means not by Beis Din, since we are discussing a case where there was no warning. If there was, there would be no difference in the ruling according to the weapon used for murder, since the witnesses watched and knew for sure that he intended purposely to give him a fatal blow. Rather, here it is talking about a case where he did not get a warning, and there is no clear awareness if it was intentional or unintentional.

ואם בכלי ברזל הכהו, “but if he struck him with a metal instrument or tool;” why did the Torah have to give us this example if it had already told us that wooden or stone vessels or tools are considered as lethal weapons? Surely it is understood that metal tools are at least as dangerous?!This is to teach us that penalties cannot be imposed on the basis of logic, especially in capital crimes, but only if the written Torah had decreed them. (Compare Rashi quoting the Talmud in Sanhedrin and by the commentaries.) A minute metal instrument, a needle is already capable of causing death, i.e. is a lethal weapon.

But it states. Meaning that when it is written, “If [he struck him] with an iron instrument… or if with a stone that can be held in the hand… or if with a wooden implement…” until “If [he pushes] out of hatred” (v. 20) perhaps it is referring to an inadvertent killer. And this was necessary [in contrast with the verses below] so that you would not say as follows: It is understandable if this refers to an inadvertent killer, that it would have had to say, “And if with an iron instrument” and all of the other cases that follow, in order to teach that he is liable for the death penalty, even if he killed inadvertently. But, if it refers to an intentional killer, what difference does it make whether he killed with an iron or any other instrument? Surely he is an intentional killer. However, when it is written afterwards (v. 21), “Or if in enmity…” until “But if suddenly” (v. 22) [it is clear that] these undoubtedly refer to an intentional killer.

With a stone. Rashi is answering the question: Why does Scripture write about “a stone” (v. 23)? Surely above it is also written about a stone, where it [apparently] also refers to an inadvertent killer. Rather, “This teaches that in its statements above…”