This whole verse is a trick. It says one thing, until the final word, which changes everything. In other words, it is a typical punchline.
We can start with the English translations. The context is Jesus’s prayer after the last supper. The “they” in this verse is from the previous verse, where Jesus says he revealed the Divine to the men that the Father gave him.
KJV: Now they have known that all things whatsoever thou hast given me are of thee.
NIV: Now they know that everything you have given me comes from you.
This, however, is not what the verse says. It is close to what it seems to say until the final word.
Let us start with what Jesus’s listeners heard, until the final word:
Now, they have learned to know because everything, as much as you gave me, from beside you."
Notice that the “as much as” is either mistranslated as “whatever” in the KJV or ignored in the NIV. Most English versions mistranslated it as “that” or “which.” This “as much as “ is important in the joke.
What changes the meaning? The final verb is plural, coming at the very end. The plural verb changes the subject to the initial "they," so it actually says:
Now, they have learned to know because they are all, as much as you gave me, from beside you."
This is a tease. Jesus is saying that his followers are all he had to work with, “all, as much as.” However, he goes on in the next verse to say nice things about his followers in a funny way.
To me, the Gospels are primarily to build an understanding of the true nature of Jesus (and therefore the Father). Jesus going around dissatisfied and criticising others of His generation does not feel compatible with His character. So I’m very happy with your important findings here Gary. Well done!
Roger