Jesus didn't mention many things in his teaching because common sense still applies.
He didn't mention marijuana, sex change operations, abortion, driving speed limits, health insurance, gun control, birth control, how to treat pets , old folks homes, public education, socialism, capitalism, along with thousands of other specific subjects. Because we are to read the Bible, pray, and study , and be part of a fellowship of brothers and by learning and understand our personal and as a body relationship with him we should see these things for what they are and act accordingly.