Genesis 21:34

And Abraham sojourned in the Philistines' land many days. Even many years, days being sometimes put for years; having entered into covenant with Abimelech, the king of the country, and settled a good correspondence with him, and having his friendship and good will, which commanded respect from his subjects, Abraham sojourned very quietly and comfortably for many years, chiefly at Beersheba; the Jewish writers say a he sojourned here twenty six years.

a Jarchi Bereshit Rabba, sect. 54. fol. 48. 4.