Mishnah 6 - Chapter 2 - Pirkei Avot

Af hu ra'ah gulgolet achat shetzafah al penei hammayim. Amar (lah). Al da'atefet, atfuch. Vesof metayefayich yetufun.

Moreover he saw a skull floating on the face of the water. He said to it: because you drowned others, they drowned you. And in the end, they that drowned you will be drowned.

He (Hillel), too, saw a certain skull floating on the water. He said to it: "Because you drowned (others), you were drowned." [You were an evildoer and you drowned them in the river, and measure for measure was it meted out to you], and in the end, your drowners will be drowned, [for it was not for them to drown you, but for beth-din; and the Holy One Blessed be He handed you over to them. For liability is relegated to the liable, and He is destined afterwards to demand your death of them.]