John Gill Commentary Numbers 13:20

"and what the land is, whether it is fat or lean, whether there is wood therein, or not. And be ye of good courage, and bring of the fruit of the land. Now the time was the time of the first-ripe grapes." — Numbers 13:20 (ASV)

And what the land [is], whether it be fat or lean
That is, what the soil of it is, whether it be rich and fertile, or whether it be poor and barren, which would be seen by the fruits it produced, this being now the fruitful season of the year; and so the Targum of Jonathan,

``and what is the praise of the land, whether its fruits are fat or lean;'' plump and full, rich and juicy, or otherwise, as their grapes, olives, &c. whether it was a land flowing with milk and honey, (Exodus 33:3) , abounding with all good things, and those of the best sort, or not:

whether there be wood thereon or not ;
timber for building, and other manual operations, or wood for fuel, which are great conveniences in a country; though the Targum of Jonathan interprets it of fruit-bearing trees, which bear fruits fit for eating, or not, as apples, pears, figs, pomegranates

and be you of good courage ;
and not be afraid of being taken up for spies, suggesting, that the power and providence of God would protect and preserve them, in which they should put their trust, and be of good heart:

and bring of the fruit of the land ;
as a sample and specimen of what it brought forth, which would serve to encourage and animate the people in general, to go up and possess it:

now the time [was] the time of the first ripe grapes ;
when they and the other summer fruits were coming to their perfection; and which was a proper season to see them in, and bring a sample of them; though Chaskuni suggests, that it was a more dangerous time to bring off fruit, because the keepers of the vineyards were then there; and hence they needed strengthening, and are bid to be of good courage; the Targum of Jonathan is,

``the day on which they went was the twenty ninth of the month Sivan, the time of the first ripe grapes;'' and as this month answers to part of our May and part of June, and it being at the latter end of that month, it must be about the middle of June; by which we may observe the forwardness of grapes in the land of Canaan, the time of vintage now drawing nigh.