The Hebrew Bible generally refers to Jews by some variation of the word Israel. (The word Jew does not appear as such until the later biblical books.) Yet, occasionally, Jews are designated as Hebrews. Yitzhaq Feder notes an interesting pattern:
[T]he bulk of occurrences of this term in the Bible appear in the speech of Egyptians and Philistines in reference to the Israelites, and a more thorough survey of these occurrences suggests that this term was indeed a derogatory racial slur. . . . The most thorough exposition of this approach is the literary critic Meir Sternberg’s epic work Hebrews between Cultures (1999), which argues that “Hebrew is a codeword for the Bible’s in-group as misrepresented from the outside by the arch-foreigner, the [Egyptian].”
This raises another question, says Feder: “If Hebrew is a derogatory term, why do we find it used by Israelites, by the narrator, and even by God?” His answer: the Torah uses the word in the book of Exodus for its dramatic effect, highlighting the reversal of roles; it is the lowly Hebrew slaves who, through divine intervention, will come to be treated with fear and deference by their once-contemptuous Egyptian masters.
Read more on TheTorah.com: http://thetorah.com/dont-call-me-hebrew/