Parashas Masei · Passuk 35:11 · TT note 2
Chabad.org — English translation + Rashi
Torah Temimah points to Sanhedrin 33b (TT note on “וְנָס שָׁמָּה רֹצֵחַ”).
E-Daf — Sanhedrin 33b · Sefaria
English: The Sages taught: From where [do we know] that one who leaves the court sentenced and someone says “I have a claim of merit for him” is returned [for retrial]? From “do not kill the innocent.” And from where that one who leaves acquitted and someone says “I have a claim of guilt” is not returned? From “do not kill the righteous.” And those liable to exile? It is derived by the Gezeirah shavah “rotzeach–rotzeach.”
Halakhic procedure for return of a verdict, extended to those liable to exile by Gezeirah shavah from the intentional murderer.
The same rules that govern return of a capital verdict apply, by the shared term “rotzeach,” to one who is sentenced to exile in a city of refuge.