What sort of Eved is the Torah referring to?
Rashi, Ramban (citing the Mechilta) and Targum Yonasan: An Eved Cana'ani, whom his master acquires forever 1 (and because the Torah never refers to an Eved Ivri as "Eved" S'tam
Whereas he only acquires an Eved Ivri for six years or until the Yovel, and he is not his property.
How do we know that the master is only Chayav Misah if the rod has been assessed and is capable of killing in the location where it struck?
Rashi: If, where the victim is a Yisrael, the Torah writes "ve'Im be'Even Yad (or bi'Cheli Eitz Yad) asher Yamus ... ", implying that the stone (or the wooden implement) was capable of killing the victim where it struck him - Kal va'Chomer an Eved, whose Din is less stringent than that of a Yisrael.
Why does the Torah mention specifically a Sheivet?
Hadar Zekenim (21): Shevet refers to authority; if he hit him for nothing, with arrogance, he is killed.
What does "Tachas Yado" mean?
Ramban: It means that he dies as a result of the stroke without having recovered. 1
Moshav Zekenim: If he hit him and sold him to another, and he died in the other's Reshus, he is exempt.
What are the connotations of "Nakom Yinakem"?
Rosh, citing Sanhedrin 52b: And all the more so, one who kills a Yisrael is killed through a sword. Yad Ramah (52b) - this is not called punishing due to a Kal ve'Chomer, for death is written explicitly, and this merely reveals which death.
Why does the Torah write "Nakom Yinakem" rather than 'Mos Yimas', as it does by other Chayvei Misos?
Oznayim la'Torah: Because,, whereas other murderers who run to hide from Beis-Din are caught by the Go'alei ha'Dam (the relatives of the victim) and taken to Beis-Din, the Eved Cana'ani has no relatives to do that, so the Torah writes "Nakom Yinakem", placing the onus on Beis-Din to catch the murderer and to judge him.
Rashi, citing the Mechilta, writes that one is liable for killing a Yisrael only if the Kli was proper to kill, and all the more so for an Eved. Why does it say call this 'punishing from a Kal v'Chomer'? The Kal v'Chomer teaches a leniency!
Hadar Zekenim, Da'as Zekenim (21): This can lead to a stringency. If one was Rodef to kill his sLa'ave with a Kli not proper to kill, if the master is not Chayav Misah for this, one who kills him is liable. 1
This is unlike Ohr Somayach (Hilchos Rotze'ach 1:8), who learns from Moser that one may kill a Rodef, even though Beis Din cannot kill him if he killed! However, if the Kli is not proper to kill, he is not truly a Rodef, and there is no Heter to kill him. This does not depend on a Kal v'Chomer! (PF)
QUESTIONS ON RASHI
Rashi writes that [killing a sLa'ave] was in the Klal of murder, and left, to teach about Yom Oh Yomayim. If so, we should need a verse to return it to the Klal!
Moshav Zekenim #1: "V'Ish Ki Yakeh Kol Nefesh Adam Mos Yumas" (Vayikra 24:17) returns it.
Moshav Zekenim #2: "Ki Kaspo Hu" implies that Yom Oh Yomayim applies only to one's sLa'ave, but the law of Rotze'ach applies to other sLa'aves.
Rashi writes that [killing a sLa'ave] was in the Klal of murder. Above (verse 14), Rashi said that "Re'ehu" excludes a Nochri. An EvedCana'ani is like a Nochri!
Moshav Zekenim: Since he does some Mitzvos, he is called Re'ehu.
Rashi writes that Nakom Yinakem teaches that he is killed through a sword. According to the opinion that choking is more severe, why is this needed? Even one who kills a Yisrael is killed through a sword!
Riva, Moshav Zekenim: One might have thought that since he has a leniency, we make a stringency in another way, and do not have two leniencies for a sLa'ave. 1
If so, how can we ever expound a Kal v'Chomer? Also, what is the source that one who kills a Yisrael is killed through a sword, if not from our verse? (PF) Riva, Hadar Zekenim (21) - the one who does not learn anything from something that left its Klal, he learns from "Shofech Dam... Damo Yishafech" (Bereishis 9:10); Da'as Zekenim (21) - or, from Eglah Arufah, due to "v'Atah Teva'er" (Kesuvos 37b).