Okay, I understand your attempt to apply literary criticism.
In that regard, have you ever read C.S. Lewis' An Experiment in Criticism, Cambridge UP, 1961?
It is a short work that provides invaluable information about literary criticism.
No, I haven't, but I'll look it up.
Back to topic on hand:
I do believe that Christ's words are to be taken at His Word unless he uses an analogy, parable, idiomatic expression, metaphor, or other literary expressions, which he has used occasionally.
You say the word occasionally, as if it's once in a blue moon that Jesus' uses the aforementioned. Much of what Jesus said was indeed analogous, parabolic, idiomatic expression, metaphoric, or other types literary expressions.
You don't there is no literary expressions in the words... "Be ye therefore perfect, even as your Father which is in heaven is perfect." It would astound me if you said no.
I don't think we can be perfect here on earth even with the help of God. For we are still in our flesh. We can never fully die off our flesh. We certainly should try, but our perfection only comes after death.
I could cite Scripture to prove my point, but for now time is not on my side.
Nevertheless, Christ's commandment to be perfect is not just "literary symbolism" because this theme is repeated throughout the scriptures by various authors. Just check the concordance where you will see more than 20 listings for the word perfect.
Just this one verse: Perfect love cast out fear.
Since we humans obviously cannot love perfectly (like God can), does that mean we will never be able to cast out fear? No.
Though God's Divine Energies and His loving kindness, we can be enabled to love God and our neighbor perfectly,
And so perfect love can cast out our fears. So too, can we become perfect.
Basically, my position all along has been we cannot be perfect here on earth. Even with God's help. For we are still in the flesh. Only until Death are we perfected; all by God's work. With that said, doesn't mean we shouldn't try, just that we're not going to reach.
For example, just because I know for a fact the older I get I will gain more and more weight, but that doesnt' mean I don't watch my weight. In fact, I strive to stay at my current weight, even though I know the truth of the matter is age will creep in causing me to 'naturally' gain weight. Hopefully, you'll understand this literary expression.