Verses with the word swim in the Old Testament (4 verses):

2 Kings 6:6
And the man of God said, Where fell it? And he shewed him the place. And he cut down a stick, and cast it in thither; and the iron did swim.

Psalms 6:6
I am weary with my groaning; all the night make I my bed to swim; I water my couch with my tears.

Isaiah 25:11
And he shall spread forth his hands in the midst of them, as he that swimmeth spreadeth forth his hands to swim: and he shall bring down their pride together with the spoils of their hands.

Ezekiel 47:5
Afterward he measured a thousand; and it was a river that I could not pass over: for the waters were risen, waters to swim in, a river that could not be passed over.