(Numbers 13:24:) THAT PLACE HE CALLED THE WADI ESHCOL, etc. This is what Scripture says (Isaiah 46:10): DECLARING THE END FROM THE BEGINNING, [AND FROM OF OLD THINGS THAT HAVE NOT YET BEEN DONE], in that everything is foreseen before the Holy One, blessed be He. Eshcol was a friend of Abraham, and he was called Eshcol on account of the cluster (eshkol) that Israel were destined to cut down from there, from his place.
Why the Spies' Valley Was Named Eshcol After Abraham's Ally
Midrash Tanchuma Buber, Sh'lach 16:1
למקום ההוא קרא נחל אשכול וגו' (שם יג כד). זש"ה מגיד מראשית אחרית [ומקד אשר לא נעשו] (ישעיה מו י), שהכל צפוי לפני הקב"ה, אשכול אוהבו של אברהם היה, ונקרא אשכול על אודות האשכול שהיו ישראל עתידין לכרות משם ממקומו.