1 Chronicles 12:19 TLB

[19] Some men from Manasseh deserted the Israeli army and joined David just as he was going into battle with the Philistines against King Saul. But as it turned out, the Philistine generals refused to let David and his men go with them. After much discussion they sent them back, for they were afraid that David and his men would imperil them by deserting to King Saul.