Why did Kayin not call the town that he was building after himself?
Ramban: Kayin did not build a town in his own name, because he was cursed, destined to move around from one place to another. 1
Oznayim la'Torah: He built it on behalf of his son, who was not included in the decree of 'Na va'Nad Tih'yeh ba'Aretz', because, had he built it in his own name, he would have violated the terms of the condition of Galus in place of death, and would have been Chayav Misah - Refer to 4:11:0.1:1 .
Why does the Torah use the strange expression, "vaY'hi Boneh Ir... ", and not "va'Yiven Ir", as the Torah usually writes?
Ramban: Because everything Kayin did was cursed, including his building efforts; He would build a little before moving away; then he would return later and continue to build. In this way, building the town was an ongoing exercise.
QUESTIONS ON RASHI
Rashi writes: "Kayin was builder of a city." But perhaps the verse means that his son Chanoch was the builder?
Gur Aryeh: It is clear that Kayin was the builder, from the end of the verse, "He named the city for his son Chanoch."
Rashi writes: "As a remembrance for his son, Chanoch." What is Rashi explaining?
Gur Aryeh: Kayin did not happen to name the city the same name as his son; rather he purposely did so, to perpetuate the name of his son.
Refer to 4:17:2.1:1 .
