The additional concubines and wives were likely an attempt by David to cement his relationship with the various tribes in Israel. Marriage bonds were a common way of doing so in the ancient Near East.1 By taking concubines and wives, David behaved in the manner that Samuel had predicted for Israel’s kings (see 1 Samuel 8:13).2
13 David prit encore des concubines et des femmes de Jérusalem, après qu'il fut venu d'Hébron, et il lui naquit encore des fils et des filles.