Jamieson, Fausset and Brown on Song of Solomon 1:9

9. horses in Pharaoh's chariots--celebrated for beauty, swiftness, and ardor, at the Red Sea (Ex 14:15). These qualities, which seem to belong to the ungodly, really belong to the saints [Moody Stuart]. The allusion may be to the horses brought at a high price by Solomon out of Egypt (2Ch 1:16, 17). So the bride is redeemed out of spiritual Egypt by the true Solomon, at an infinite price (Is 51:1; 1Pe 1:18, 19). But the deliverance from Pharaoh at the Red Sea accords with the allusion to the tabernacle (So 1:5; 3:6, 7); it rightly is put at the beginning of the Church's call. The ardor and beauty of the bride are the point of comparison; (So 1:4) "run"; (So 1:5) "comely." Also, like Pharaoh's horses, she forms a great company (Re 19:7, 14). As Jesus Christ is both Shepherd and Conqueror, so believers are not only His sheep, but also, as a Church militant now, His chariots and horses (So 6:4).