"The deep clothes itself with a garment; over the mountains the waters stood. Rabbi Yehuda and Rabbi Nechemia asked about the earth, why it stands upon the waters, as it is said, 'who lays the beams of His upper chambers in the waters, Who makes the clouds His chariot, Who walks upon the wings of the wind' (Psalms 104:3). And [about] the waters [standing] upon the mountains, as it is said, 'The waters stood above the mountains' (Psalms 104:6).
And it is written, 'The mountains rose, the valleys sank, to the place that You founded for them' (Psalms 104:8). This is the ocean, whose boundary was set that it should not pass over. He sends forth springs into the valleys; between the mountains they flow. On them, the fowl of the heavens dwell.
Rabbi Yishmael and Rabbi Akiva [interpreted the verse differently]. Rabbi Akiva said, 'These are the ministering angels.' Rabbi Yishmael said to him, 'Akiva, your words have come to an end; go to [teach about] plagues and tents.' Rabbi Yishmael said, 'This refers to the birds that dwell upon the trees, whose trills are from before the Lord of the Universe, as it is said, 'Amid the arrows they give voice' (Psalms 11:2).'
Rabbi Yehudah said, 'How great is what you said, as it says, 'And their wings spread out beautifully' (Daniel 4:9).' And Samuel said, 'There are three things about which we stand [in wonder] and know not what they are: the way of a ship in the midst of the sea, the way of a serpent upon a rock, the way of a man with a maiden' (Proverbs 30:18-19). The one who hammers a stake into the ground and is heard from a distance; the voice of a horse when it runs and snorts; 'Amid the arrows they give voice.'" (Psalms 11:2)