Sometimes students read a biblical text out of context. One case in point comes from Jesus's saying of a proverb, "Doctor, cure yourself" (Lk 4:23). They argue that the preacher who has all kinds of maladies/sins can use this text for preaching healing and self-care. But this text is about neither healing nor a sound doctor.
The meaning of Luke 4:23 or the whole passage can be decided at two levels which must be distinguished in a critical study: from the historical Jesus and the Jesus reflected in/by Luke (the Lukan Jesus). If Jesus told this saying (4:23), including all he said in this passage (4:16-30), we have to wonder about the possibilities of meaning he wanted to communicate. One possibility is that given his village people’s disbelief about him (“Is not this Joseph’s son?” 4.22), he retorts them and rejects their view that he is incompetent or inconsistent as a teacher, as a similar case can be made with a bad doctor. This is the context where Jesus uses this proverbial saying, “Doctor, heal yourself.” But this exact form of proverb has not been discovered in both classical or Rabbinic literature. The approximate form of reference has to do with “a bad doctor,” who is unable to function well for various reasons in various contexts. There are many texts and contexts which address various issues regarding a bad doctor.
Otherwise, this proverb that Jesus used should not be taught apart from the context which he addresses. His concern here is not the doctor’s abilities to cure others or the importance of self-care or perfection before helping others. The problem is that his village people do not believe his teaching/preaching.
From the Lukan perspective, regardless of where this material of Lk 4:16-30 comes from, there are clear Lukan emphases in this passage. This is Jesus’s first public teaching/preaching which happens in his hometown, in the very synagogue. He did a great job, and his hometown people were amazed at his gracious words. But still, they did not have trust with him because he was from a meager family they all knew so well (Mary and Joseph). So the Lukan Jesus says: “Doubtless you will quote to me this proverb, 'Doctor, cure yourself!' And you will say, 'Do here also in your hometown the things that we have heard you did at Capernaum.'" The problem is that they cannot believe that Jesus is the Messiah. In this context, “cure yourself” is a pejorative saying that rejects Jesus. Interestingly, because of Jews’ disbelief or rejection of Jesus, the gospel moves to the Gentiles. That is a logical conclusion that Luke-Acts follows. So, right after this saying, Jesus preaches about God’s preferential option for the Gentiles. Elijah and Elisha were involved in the salvation of non-Israelites.
The conclusion is that, from the Lukan Jesus perspective or from the historical Jesus’s, “cure yourself” must be interpreted in its literary context. In my view, one cannot dissect this saying from the entire text/passage and explore the importance of perfection or self-care for the preacher before helping others. That is an overstretch or some people say it is an eisegesis.