1)
What is the significance of the 'many days that Avraham sojourned in the Land of the Pelishtim'?
1.
Rashi: It means that following the twenty-five years that he spent in Chevron (from the age of 75 to 99), 1 he spent twenty-six years in Be'er-Sheva (from the age of 99 to a 125, twelve years before the Akeidah) - after which he returned to Chevron.