Midrash su Numeri 13:24

16 (Numb. 13:24) “That place was called Wadi Eshcol”: This text is related (to Is. 46:10), “Declaring the end from the beginning, and from of old, things that have not yet happened,” in that everything is foreseen by the Holy One, blessed be He. Eshcol (according to Gen. 14:24) was Abraham's friend, and he was called Eshcol because of the grape cluster (eshkol), which Israel was going to cut from his place.

"and they came to the river-bed of Eshkol": so-called by reason of the cluster (eshkol) of grapes (that they were to take from there [viz. Bamidbar 13:24]) Similarly, (Shemoth 3:1) "and he came to the mountain of G-d to Chorev": so-called because of what would occur there in the future.