"And they took of the fruit of the land in their hands, and brought it down unto us, and brought us word again, and said, It is a good land which the LORD our God doth give us." (Deuteronomy 1: 25)
The massive vines of grapes speak of Jesus.
He was hanging between heaven and earth, between two others.
His blood is represented in the wine (or juice, or anything else) which we drink at Communion:
"And he said unto them, This is my blood of the new testament, which is shed for many." (Mark 14: 24)
Paul would write to the Corinthians:
"After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me." (1 Corinthians 11: 25)
The Promised Land, the good land which the LORD gave the Israelites, is a picture of our Lord Jesus, who God the Father gave to us:
"Come unto me, all ye that labour and are heavy laden, and I will give you rest." (Matthew 11: 28)
And then in Hebrews:
"8For if Jesus [Joshua] had given them rest, then would he not afterward have spoken of another day. 9There remaineth therefore a rest to the people of God. 10For he that is entered into his rest, he also hath ceased from his own works, as God did from his. 11Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief." (Hebrews 4: 8-11)
He is our rest, and God's greatest gift to us:
"For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." (John 3: 16)
and then in Romans:
"He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?" (Romans 8: 32)
The grapes which the spies had brought to the Israelites were a perfect representation of Jesus. Just as Jesus hung on the Cross of our righteousness, the perfect sign of God's love for us, so to we can believe on Him for all things, that He is a good God!