Deuteronomy 17:16
14 When you come to the land the Lord your God is giving you and take it over and live in it and then say, “I will select a king like all the nations surrounding me,” 15 you must select without fail a king whom the Lord your God chooses. From among your fellow citizens you must appoint a king—you may not designate a foreigner who is not one of your fellow Israelites. 16 Moreover, he must not accumulate horses for himself or allow the people to return to Egypt to do so, for the Lord has said you must never again return that way. 17 Furthermore, he must not marry many wives lest his affections turn aside, and he must not accumulate much silver and gold. 18 When he sits on his royal throne he must make a copy of this law on a scroll given to him by the Levitical priests.
1 Kings 10:27
25 Year after year visitors brought their gifts, which included items of silver, items of gold, clothes, perfume, spices, horses, and mules. 26 Solomon accumulated chariots and horses. He had 1,400 chariots and 12,000 horses. He kept them in assigned cities and in Jerusalem. 27 The king made silver as plentiful in Jerusalem as stones; cedar was as plentiful as sycamore fig trees are in the foothills. 28 Solomon acquired his horses from Egypt and from Que; the king’s traders purchased them from Que. 29 They paid 600 silver pieces for each chariot from Egypt and 150 silver pieces for each horse. They also sold chariots and horses to all the kings of the Hittites and to the kings of Syria.
Notes and References
"... In Deuteronomy 17, the selection process for kingship had been sketched for the people: they were to appoint a man chosen by God, from among their “brothers,” not a foreigner (verse 15). One curious stipulation was that he was not to acquire “a great number of horses for himself nor make the people return to Egypt to get more of them” (verse 16). In fact, Hebrew kingship was based on two covenants that defined the duties of the crown toward God and toward the people: his relationship to God was “conceived as that of a vassal toward his overlord. He was installed in the office by divine election, on condition that he remain loyal to God and keep his laws (2 Samuel 23:5; Psalm 132:12). Whenever the king transgressed the terms of this covenant, he could be criticized by priests and prophets.” ... In building his army and outfitting his men, King Solomon displayed his taste for opulence. His shields of hammered gold (1 Kings 10:16), his chariots and horses, his fleet of trading ships “carrying gold, silver and ivory, and apes and baboons” led the scribe to observe: “King Solomon was greater in riches and wisdom than all the other kings of the earth” (1 Kings 10:22–23). His main strategy for maintaining international power was less by force than by marriage. He “loved many foreign women” starting with the Pharaoh’s daughter, leading eventually to “Moabites, Ammonites, Edomites, Sidonians, and Hittites” (1 Kings 10:27) ..."
Tischler, Nancy M. All Things in the Bible (pp. 339-341) Greenwood Press, 2006