The term "casing out" has a few antonyms worth mentioning. Instead of casing out, you could use the term "welcoming in," which means to invite or accept someone or something. Another antonym is "ignoring," which means to pay no attention to or disregard something. "Protecting" could also be used as an antonym, which means to keep something safe from harm or danger. Furthermore, "embracing" is an antonym that could be used, which means to accept or adopt something willingly. Lastly, "releasing" could be an antonym, meaning to let go of or set something free.