Makkot 10 - Arrangements for the Unintentional Killer
The phrase " and he shall flee to one of those cities and live " teaches that we have to provide him with arrangements that will enable him to live. If he is a student of Torah, we exile his teacher with him, because a student cannot survive without the one who teaches him Torah. From here we see that a person should not teach a disciple who is not of good character. Furthermore, if the teacher is exiled, his academy is exiled with him.
Rav Chama used to say, "If God guides sinners on the way , He surely guides the righteous."
Resh Lakish used to explain the phrase " but God caused it to come to his hand " with this example. Two people killed a person, one inadvertently, and one intentionally, but there were no witnesses against both. God causes one to sit under a ladder while the other one descends, falls on him, and kills him, this time with witnesses. One is thus executed, and the other one exiled.
Art: Isaac Snowman - Three Rabbis Of Jerusalem