19 And of Manasseh there have fallen unto David in his coming with the Philistines against Israel to battle -- and they helped them not, for by counsel the princes of the Philistines sent him away, saying, `With our heads he doth fall unto his master Saul.' --
19
Some of the tribe of Manasseh defected to David when he went with the Philistines to fight against Saul. (He and his men did not help the Philistines because, after consultation, their rulers sent him away. They said, “It will cost us our heads if he deserts to his master Saul.”)
Young's Literal Translation is in the public domain.