וְלֹ֤א יַרְבֶּה־לּוֹ֙ נָשִׁ֔ים וְלֹ֥א יָס֖וּר לְבָב֑וֹ וְכֶ֣סֶף וְזָהָ֔ב לֹ֥א יַרְבֶּה־לּ֖וֹ מְאֹֽד׃
Neither shall he multiply wives to himself, that his heart turn not away; neither shall he greatly multiply to himself silver and gold.
Targum Jonathan on Deuteronomy
Neither shall he multiply to him wives above eighteen, lest they pervert his heart; nor shall he increase to him silver or gold, lest his heart be greatly lifted up, and he rebel against the God of heaven.