John Wesley on 2 Samuel 3:3

Geshur - A part of Syria, northward from the land of Israel. Her he married, as it may seem, in policy, that he might have a powerful friend and ally to assist him against Ishbosheth's party in the north, whilst himself opposed him in the southern parts. But he paid dear for making piety give place to policy, as the history of Absolom sheweth.