The question cannot be answered by working up from the text, exegesis, or what the site wrongly calls hermeneutics, borne out by the definitions that all modern scholars give to those words. Exegesis is an interpretational method using grammar to determine how different words in a sentence relate to each other. For example, according to the rules of Greek grammar, what does the word "this" refer to in Ephesians 2:8? Grace or faith?
Hermeneutics is the study of different interpretational methods, including exegesis. Different situations call for different hermeneutical methods. For example, a standard approach is to use allegory to interpret poetical passages. A very useful study is the examination of how Jewish scholars interpret Biblical passages using different hermeneutical methods called PARDES. We find Paul used this method in finding the explanation for why Israel found herself having two covenants in her midst by comparing it with the situation of Abraham having both a slave and a son in his family.
The answer to the question will come from interpreting the passage by using the method of studying what the writer was teaching his students and what the lesson means today. For example Paul tells women to cover their hair. Today it means that women believers should not dress like loose women. To confirm that this is the PRINCIPLE that was taught, we need to find other passages that teach the same lesson.
Jesus told His followers not to behave like the Pharisees. Today the teaching can be shown to mean not to behave like people who live to serve self.
Are there other teachings that mean we should not live to serve self?
Sure, many, like this (bolded text mine, added for expansion, amplification or substituition for a wrong translation choice):
Matthew 6:24“No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to one and despise the other. You cannot serve God and wealth (material things). 25“For this reason I say to you, do not be worried about your life, as to what you will eat or what you will drink; nor for your body, as to what you will put on. Is not life more than food, and the body more than clothing?
So what was Jesus alluding to when He asked, "Do you not yet understand"?
He was hinting that they should realise they were in the same situation as Israel in the Exodus:
Exodus 4:8“If they will not believe you or heed the witness of the first sign, they may believe the witness of the last sign. 9“But if they will not believe even these two signs or heed what you say, then you shall take some water from the Nile and pour it on the dry ground; and the water which you take from the Nile will become blood on the dry ground.”
In other words, He was hinting that the signs were not the means by which God people were to live, working for bread that perishes, but they were given to build up the faith of Israel, courage to destroy Canaanites, worldy living, another version of Egypt. Similarly, after seeing that God would take care of the essentials ( Matthew 6:32) the disciples should by now not be worrying about those things, not be materialistic, like the Pharisees, because God had taught them like He had taught Israel, man does not live by bread alone, but by every word that proceeds from the mouth of God ( the words being to come out of Egypt, mammon, serving self interest, worldly ways, fight it, destroy it, because only then will we really live). Which, by the way, is also the lesson, the principle, taught for today.
All Scripture from the NASB.