Deuteronomy 19:11

וכי יהיה איש שנא לרעהו BUT IF A MAN HATE HIS FELLOW [AND LIE IN WAIT FOR HIM] — It is through his hatred that he comes to such a point as to “lie in wait for him”. From here they (the Rabbis) derived their statement: If a man transgresses a light command he will in the end transgress a weighty command; — because he transgressed the command (Leviticus 19:17) “Thou shalt not hate thy brother in thine heart”, he will in the end come to such a point as to shed blood. It is for this reason that it is stated here, apparently redundantly, “but if a man hate his fellow [and lie in wait for him]”, for it ought to have written only: “But if a man rise up and lie in wait for his fellow and smite him mortally” (Sifrei Devarim 186:2).

וְכִֽי־יִהְיֶ֥ה אִישׁ֙ שֹׂנֵ֣א לְרֵעֵ֔הוּ וְאָ֤רַב לוֹ֙ וְקָ֣ם עָלָ֔יו וְהִכָּ֥הוּ נֶ֖פֶשׁ וָמֵ֑ת וְנָ֕ס אֶל־אַחַ֖ת הֶעָרִ֥ים הָאֵֽל׃

But if any man hate his neighbour, and lie in wait for him, and rise up against him, and smite him mortally that he die, and then flees into one of these cities: