Charles Ellicott Commentary 1 Samuel 25:6

"and thus shall ye say to him that liveth [in prosperity], Peace be unto thee, and peace be to thy house, and peace be unto all that thou hast." — 1 Samuel 25:6 (ASV)

And in this way you shall say. — On such a festive occasion near a town or village, an Arab sheik of the neighbouring desert would hardly fail to put in a word, either in person or by message; and his message, both in form and substance, would be only a transcript of David’s. — Robinson, Palestine, p. 201.

To him who lives in prosperity. — Considerable diversity of opinion exists regarding the meaning of the Hebrew original here, lechai. The Vulgate alters the text slightly and renders it “to my brother.” The Septuagint has an impossible translation — “eis horas,” meaning for times or for seasons. It is better, however, to understand it as a popular expression of congratulation, not found, as Lange well puts it, in the literary language. Luther also renders it “glück auf,” meaning “may it turn out well” or “may you be prosperous.” The famous Hebrew commentator Raschi, and also the Babylonian Talmud, apparently understand it in this sense.