אַ֭חֲרָיו יָאִ֣יר נָתִ֑יב יַחְשֹׁ֖ב תְּה֣וֹם לְשֵׂיבָֽה׃
그 마음이 돌 같이 단단하니 그 단단함이 맷돌 아랫짝 같구나
Rashi on Job
He makes a path shine after him When he swims and floats in the sea, he makes the path of the deep shine, for at the time he swims, there is no water because of the speed of his swimming.
Rashi on Job
he considers the deep to be hoary To him, the deep is considered to be weak and feeble.