The blast of God's nostrils corresponds to the natural agency, the east wind Exodus 14:21, which drove the waters back: on the north the waters rose high, overhanging the sands, but kept back by the strongwind: on the south they laid in massive rollers, kept down by the same agency in the deep bed of the Red Sea.

The depths were congealed - The strong east wind (Exodus 14:21) employed to dry the bottom of the sea, is here represented as the blast of God's nostrils that had congealed or frozen the waters, so that they stood in heaps like a wall on the right hand and on the left.

Exodus 15:8

And with the blast of thy nostrils the waters were gathered together,.... From the bottom of the sea, and divided and laid on heaps; and this by a strong east wind, called the blast of the nostrils of the Lord, because as easily brought by him as a man's breath or wind is drawn through his nostrils; and thus Christ with the breath of his mouth, and the brightness of his coming, will destroy antichrist, 2 Thessalonians 2:8.

the floods stood upright as an heap; though a fluid body, yet by the power of Christ were raised up and continued upright, firm and consistent; as things dry and solid may be laid and heaped up on one another, and remain firm and stable; and so did the waters of the sea, they stood like a wall, and were as firm as a rock; while the Israelites passed between them, they stood upright, and lift up their hands, as if they blessed them; or blessed God for the deliverance of them, or in admiration of it; see Exodus 14:22,

Thus had Jehovah annihilated the Egyptians. "And by the breath of Thy nostrils (i.e., the strong east wind sent by God, which is described as the blast of the breath of His nostrils; cf. Psalm 18:16) the waters heaped themselves up (piled themselves up, so that it was possible to go between them like walls); the flowing ones stood like a heap" (נד cumulus; it occurs in Joshua 3:13, Joshua 3:16, and Psalm 33:7; Psalm 78:13, where it is borrowed from this passage. מזלים: the running, flowing ones; a poetic epithet applied to waves, rivers, or brooks, Psalm 78:16, Psalm 78:44; Isaiah 44:3). "The waves congealed in the heart of the sea:" a poetical description of the piling up of the waves like solid masses.

And with the blast of thy nostrils the waters were gathered together, the floods stood upright as an heap, and the depths were congealed in the heart of the sea.

15:8 With the blast of thy nostrils - By thine anger: The depths were congealed - Stood still, as if they had been frozen: In the heart of the sea - The midst of it.

15:1-21 This song is the most ancient we know of. It is a holy song, to the honour of God, to exalt his name, and celebrate his praise, and his only, not in the least to magnify any man. Holiness to the Lord is in every part of it. It may be considered as typical, and prophetical of the final destruction of the enemies of the church. Happy the people whose God is the Lord. They have work to do, temptations to grapple with, and afflictions to bear, and are weak in themselves; but his grace is their strength. They are often in sorrow, but in him they have comfort; he is their song. Sin, and death, and hell threaten them, but he is, and will be their salvation. The Lord is a God of almighty power, and woe to those that strive with their Maker! He is a God of matchless perfection; he is glorious in holiness; his holiness is his glory. His holiness appears in the hatred of sin, and his wrath against obstinate sinners. It appears in the deliverance of Israel, and his faithfulness to his own promise. He is fearful in praises; that which is matter of praise to the servants of God, is very dreadful to his enemies. He is doing wonders, things out of the common course of nature; wondrous to those in whose favour they are wrought, who are so unworthy, that they had no reason to expect them. There were wonders of power and wonders of grace; in both, God was to be humbly adored.