"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.
"and they spied it out": traversing its boundaries, length and width.
(Devarim 1:25) "And they took in their hand from the fruit of the land": R. Shimon said: Shameful are these men who took in their hand (such luxuriant fruits [to downgrade their worth]) as one would take in his hand an issar's worth of figs or grapes.