פֶּן־יִרְדֹּף֩ גֹּאֵ֨ל הַדָּ֜ם אַחֲרֵ֣י הָרֹצֵ֗חַ כִּי־יֵחַם֮ לְבָבוֹ֒ וְהִשִּׂיג֛וֹ כִּֽי־יִרְבֶּ֥ה הַדֶּ֖רֶךְ וְהִכָּ֣הוּ נָ֑פֶשׁ וְלוֹ֙ אֵ֣ין מִשְׁפַּט־מָ֔וֶת כִּ֠י לֹ֣א שֹׂנֵ֥א ה֛וּא ל֖וֹ מִתְּמ֥וֹל שִׁלְשֽׁוֹם׃
Para que o vingador do sangue não persiga o assassino enquanto seu coração estiver quente, e o alcance porque o caminho é longo, e o mate, quando ele não merece a pena de morte, pois ele não o odiava desde ontem nem anteontem.
Rashi
פן ירדף גאל הדם LEST THE AVENGER OF THE BLOOD PURSUE [THE SLAYER] — therefore I tell you to prepare the way for you and [to prepare] many cities of refuge.
Chizkuni
והכהו נפש, “and strike him fatally;” there is a word missing in this phrase, i.e. the word מכת “a blow;”.
Ibn Ezra
strike him mortally [literally: strike his life] an elliptical construction, meaning “strike him a mortal blow ” — i.e., strike him a blow in a place from which his life will leave him.