Why Moses Set the Three Cities of Refuge Toward the Sunrise

"Then Moses set apart three cities" (Deuteronomy 4:41). Moses our teacher, peace be upon him, said: Even though these cities on the other side of the Jordan do not afford refuge until those in the land of Canaan are designated, nevertheless, a commandment that comes to my hand I will fulfill. And why did he set them apart toward the sunrise? He learned it from Cain, who murdered his brother and was exiled to the east, as it is said, "And he dwelt in the land of Nod, on the east of Eden" (Genesis 4:16). Another interpretation: "toward the sunrise" — and it shall be for the murderers.