All Israel refers to all the people of Israel and is not to be taken as a mere geographical reference.
From Dan to Beer-sheba: the city of Dan, located at the southern foot of Mount Hermon, was the northernmost limit of ancient Israel. Beer-sheba, located in the Judean Negeb, stood as the southernmost point. From Dan to Beer-sheba became a fixed phrase to refer to the entire country from the extreme north to the extreme south (see, for example, Judges 20.1; 2 Sam 3.10; 17.11; 24.2, 15; 1 Kgs 4.25; 1 Chr 21.2).
Since many readers will not know that these two towns represent the extreme northern and southern borders of Israel, this information should be made explicit. There are several ways to do so: (1) Place this information in a footnote, as do Bible en français courant and Traduction œcuménique de la Bible. (2) Keep the names of the towns in the text and make explicit their location; that is, “from the town of Dan in the north to the town of Beersheba in the south” (Contemporary English Version, also Parola Del Signore: La Bibbia in Lingua Corrente consistently, and Nova Tradução na Linguagem de Hoje in Judges 20.1). (3) Omit the names and translate the sense of this fixed phrase; that is, “from one end of the country to the other,” as does Good News Translation.
Solution (2) has the advantage of translating the meaning while also reinforcing for the reader the locations of these two towns, and it is recommended as preferable. In either option 1 or 2, it will be important to add the classifier term “town” to indicate to readers what Dan and Beer-sheba refer to.
The Hebrew participle rendered was established is the same as that translated “faithful” and “sure” in 2.35 (see the comments there). New Jewish Publication Society’s Tanakh says “was trustworthy as a prophet of the LORD.” Similarly New Revised Standard Version, “Samuel was a trustworthy prophet of the LORD.” See also Parola Del Signore: La Bibbia in Lingua Corrente, “Samuel was a true prophet of the LORD” (see the comments on verse 19).
The word prophet may be difficult to translate in many languages. While it is true that the prophets of the Old Testament did sometimes foretell the future, this is not the primary focus of the term. What is more important about the function of the prophets is that they communicated to people on behalf of God. Many languages have special terms to refer to the spokesman or herald of a chief. It is often possible to use this term in an expression meaning “herald [or spokesman] for God” or “one who proclaims God’s message.” In other languages it is possible to say “a person sent by God.” Translators are advised to avoid the idea of “foreteller of the future.”
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on the First and Second Books of Samuel, Volume 1. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here .