Oh, you are referring to Leviticus 11. Those were the rules instructed by God written by Moses to the Hebrews (now modern day Israelites or Israelis). They were instructed to not eat specific animals because of the animal's daily diet; thus, it was unhealthy or unclean. For the sake of spreading the gospel not only to Israel but also to the Gentiles (anyone who isn't a descendant of Abraham). Read Acts 10 for an exhibition, starting at verse 14 if you wish (https://www.biblegateway.com/passage/?search=Acts+10&version=NASB).