Deuteronomy 17:16

Not multiply horses] The horse is here forbidden, not as an article of luxury but as an instrument of warfare, in which the kings of Israel are not to trust: cp. Psalms 20:7; Psalms 33:16; Psalms 147:10. Canaan was not suitable for cavalry, and the conquest of the country was effected by infantry, whose superiority was due to the hilly nature of the country. Solomon imported horses from Egypt (1 Kings 10:26; 1 Kings 10:28), and similar reliance upon Egypt was a frequent snare to the Israelites against which the prophets raised a warning voice: see Isaiah 31:1; Ezekiel 17:15. Horses were also dedicated to the sun-god by the idolatrous kings of Israel: see 2 Kings 23:11, and on Exodus 9:8.