sitifan“Is there any difference in meaning between "eat of" and "eat"?”
There is more difference in style than in meaning, although the meaning is slightly different. The Bible is written in very old English, including very archaic "partitive" structures using "of".
eat of it ~ eat some/any of it ~ eat some/any part of it.
It's not exactly the same as "eat it". That would imply "all of it".
The partitive is not used in modern English except in imitation of archaic religious style.
Here are others:
Then the Lord said to Adam, You shall not now take of it, for it has been assigned to the cherubim and the flaming sword ...And it came to pass that when he said these words, he commanded his disciples that they should take of the wine of the cup and drink of it ...
Eve was tempted by the lying words of the Snake and desired to taste of the forbidden fruit but she was afraid to taste of it alone ...
CJ