Moreover, some from Manasseh crossed over to David, when he went forth with the Philistines against Saul, so that he might fight. But he did not fight with them. For the leaders of the Philistines, taking counsel, sent him back, saying, "To the peril of our own heads, he will return to his lord, Saul.
Other versions
King James Version
And there fell some of Manasseh to David, when he came with the Philistines against Saul to battle: but they helped them not: for the lords of the Philistines upon advisement sent him away, saying, He will fall to his master Saul to the jeopardy of our heads. English Standard Version
Some of the men of Manasseh deserted to David when he came with the Philistines for the battle against Saul. (Yet he did not help them, for the rulers of the Philistines took counsel and sent him away, saying, "At peril to our heads he will desert to his master Saul.")New International Version
Some of the men 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.")