HEBREWS | It is clear from the use of the term 'Hebrew' in 1 Samuel that the author does not see it as exactly interchangeable with 'Israelite.' In the main, this is an ethnic designator used by foreigners - the Philistines - to refer to the Israelites. The Philistines consider the Israelites to be Hebrews. However, there are others Hebrews who are not exactly identifiable as Israelites, and it is not clear that the Israelites think of themselves as Hebrews.
(6) The Philistines heard the noise of the shouting and they wondered, “Why is there such a loud shouting in the camp of the Hebrews?” And when they learned that the Ark of the LORD had come to the camp,
(9) Brace yourselves and be men, O Philistines! Or you will become slaves to the Hebrews as they were slaves to you. Be men and fight!”
ETHNOGENESIS | It is worth noting that this memory recalls the period before the establishment of the Hebrew kingdoms, and - as Israel Finkelstein suggests - 'Israel' may not have been the settled identity of the various ethnic groups in the hill country. 'Hebrew,' then, may refer to a class of people rather than a self-identified ethnic group. Israel may have been a Hebrew group, but not all Hebrews considered themselves part of an emerging Israelite ethnic identity.
(3) Jonathan struck down the Philistine prefect in Geba; and the Philistines heard about it. Saul had the ram’s horn sounded throughout the land, saying, “Let the Hebrews hear.”-d
(7) Some Hebrews crossed the Jordan, [to] the territory of Gad and Gilead. Saul was still at Gilgal, and the rest of the people rallied to him in alarm.d
CONFLICT | Ethnic identities are largely a matter of self-ascription and can change. Conflict between groups has often proven to be a key motivator in the formation of ethnic identity and difference. 1 Samuel recalls a time probably in the second half of the eleventh century BCE when urban settlement was underway in the hill country. At this time the Palastu - the Philistines - had colonised and fortified the coastal plain. These 'Sea People,' an essentially foreign people in the Levant, put significant pressure on the Hebrew settlers and this may have stimulated the process of ethnogenesis. The demand of 'the people' for a king should be understood as part of this process.
(19) No smith was to be found in all the land of Israel, for the Philistines were afraid that the Hebrews would make swords or spears.
(11) They both showed themselves to the Philistine outpost and the Philistines said, “Look, some Hebrews are coming out of the holes where they have been hiding.”
SHIFTING ALLEGIANCES | Not all Hebrew understood themselves to be part of Israel, and the Israelites did not necessarily see all Hebrews to be part of the community of Israel. There may have been closer tribal, clan, cultic, and linguistic relations between the Hebrews and the Israelites than between the Hebrews and the Philistines, but this closeness may well have accentuated division. Not all Hebrews would have been content with Israel's growing power and influence over the hill country. Sometimes we get the impression Hebrews were a class of bandits and/or mercenaries.
(21) And the Hebrews who had previously sided with the Philistines, who had come up with them in the army [from] round about—they too joined the Israelites-b who were with Saul and Jonathan.
(3) The Philistine officers asked, “Who are those Hebrews?” “Why, that’s David, the servant of King Saul of Israel,” Achish answered the Philistine officers. “He has been with me for a year or more,-a and I have found no fault in him from the day he defected until now.”