OET interlinear GEN 4:15

uW Translation Notes:

Note 1 topic: writing-quotations

וַ⁠יֹּ֧אמֶר ל֣⁠וֹ יְהוָ֗ה

and=he/it_said to=him/it YHWH

Alternate translation: [So Yahweh said to him] or [Yahweh said to Cain]

Note 2 topic: translate-textvariants

לָ⁠כֵן֙

for=so/thus/hence

That is what the Hebrew text has. Instead of that text, some ancient translations (such as the Septuagint) and many modern translations have: “Not so/true.” or “That will not happen because.” The textual variant that you do not use in your translation could be put in a footnote. Alternate translation: [In that case]

Note 3 topic: figures-of-speech / explicit

כָּל־הֹרֵ֣ג קַ֔יִן & יֻקָּ֑ם

all/each/any/every killing_of Qayin/(Cain) & he/it_will_be_avenged/punished

What God says here implies that he will do something to prevent people from killing Cain; he is not just talking about punishing them if they kill him. If necessary, you could make that explicit in your translation. Alternate translation: [I will warn everyone that if anyone kills you, I will take revenge on him for you] or [I will make it clear to everyone that I will take revenge on anyone who kills you]

Note 4 topic: translate-unknown

וַ⁠יָּ֨שֶׂם יְהוָ֤ה לְ⁠קַ֨יִן֙ א֔וֹת

and=he/it_assigned YHWH to/for=Qayin/(Cain) sign/signal/evidence

We do not know exactly how Yahweh marked Cain, so keep your translation of this clause general (like the Hebrew text is). Alternate translation: [Then he put a special symbol on Cain] or [Then he marked Cain with a special mark]

Note 5 topic: figures-of-speech / idiom

לְ⁠בִלְתִּ֥י הַכּוֹת־אֹת֖⁠וֹ כָּל־מֹצְאֽ⁠וֹ

to=not to_strike/beat DOM=him/it all/each/any/every finding=him/it

The phrase strike him is used here as a common expression that means “kill him.” Do what is best in your language. Alternate translation: [so that anyone who saw him would not kill him]