Parashas Masei · Passuk 35:19 · TT note 1
Chabad.org — English translation + Rashi
Torah Temimah points to Yerushalmi Makkos 2:5 (TT note on “גֹּאֵל הַדָּם”).
English: Rabbi Sheila taught: In view of the verse “the blood-avenger shall put the murderer to death,” one who struck his own son — the second son does not become blood-avenger to put his father to death; but a brother who struck his brother — the second brother does become blood-avenger.
Halakhic limit on who may serve as blood-avenger within the family.
A son may not avenge his father’s killing of a sibling; a brother may avenge the killing of another brother.