Jesus responds with a proverb to teach the man about being his disciple. Jesus means that a person is not suitable for the kingdom to God if he focuses on people in his past instead of following Jesus. (See: [[rc://en/ta/man/translate/writing-proverbs]] and [[rc://en/ta/man/translate/figs-explicit]])
Here "put his hand to" is an idiom that means the person started to do something. AT: "No one who has started to plow his field" or "No one who has started to prepare his field" (See: [[rc://en/ta/man/translate/figs-idiom]] and [[rc://en/ta/man/translate/translate-unknown]])