And he moved from there: he moved means that Isaac migrated with his family, servants, belongings, and animals in search of pasture for his flocks and herds. There has no particular geographical reference but means the place in which he had been camped in verse 21.
Over that they did not quarrel: they refers to the same people as in verse 21.
Called its name Rehoboth: its refers to that well. See Revised Standard Version footnote for Rehoboth. This name first occurred in 10.11. The word is in a plural form. It is used in the singular in David’s song in 2 Sam 22.20, “a broad place,” as a figure of freedom from danger or distress, and with the same sense in Psa 18.19. The sense of Rehoboth is given in the explanation has made room for us, which is literally “has broadened for us.” In other words the LORD has given us a place where we can spread out and be free from the pressure of others. In some languages there is a term for a place or space that is vacant or not being used by other people, “an empty place.” Good News Translation‘s rendering is adequate: “The LORD has given us freedom to live in the land.”
Interpreters identify this well with one known later as “Wadi Ruhebe,” located some thirty kilometers (twenty miles) southwest of Beersheba.
As a result of the space to live in peace, the quotation goes on to add and we shall be fruitful in the land. Fruitful is the same term as in 1.22, 28; 8.17, and means to increase in numbers through reproduction. Since the reference is to we, some interpreters take it to mean the people, Isaac and his descendants. Others understand it more generally to refer to an increase in everything, and so Good News Translation has “will be prosperous.” The sense of this is expressed in one translation as “and our work can go ahead well here.” Either view is possible. The pronoun we is inclusive in this context.
Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .