Charles Ellicott Commentary 1 Samuel 29:10

"Wherefore now rise up early in the morning with the servants of thy lord that are come with thee; and as soon as ye are up early in the morning, and have light, depart." — 1 Samuel 29:10 (ASV)

With thy master’s servants. —These words have perplexed expositors. It is hardly the expression we would expect Achish to use for David’s followers. All Israelites were, of course, “subjects of Saul,” but the term would hardly be used except by someone hostile to David, as Nabal was; he once (1 Samuel 25:10) used an insulting term of a similar nature toward David. Achish, we know, always seemed kindly disposed to the outlawed son of Jesse.

A probable suggestion has, however, been recently made, that the reference here is to those tribes of Manasseh (Compare to 1 Chronicles 12:19–21) who had only recently come over to David. Was it not also possible that these very Manassites, who had only very recently deserted the king’s cause for David’s, were known to some of the Philistines as Saul’s soldiers, and that their suspicions had been awakened in the first place by finding them marching under David’s standard in the Gath division?