Got verbal premision to detect but not written, advice?

Hey everyone, I’m new to the hobby but I am enjoying it a lot so far. I live a little bit out in the country and in my research I’ve found apparently two houses from the mid to late 1800s were once located in this old farm field across from me and just at the end of the road in another field. Both these fields are owned by and old farmer and I finally got the chance to approach him yesterday. I told him that I was wondering if I could metal detect his fields and he said sure, we talked a bit more and found of some connections of how we know some of the same people. He knew some of my family members on a business level and I knew a friend of his as an old co worker. All that being said, I gave him my number to contact me and he told me it was fine and to have fun finding horse shoes. It was really pleasant, I know everyone here stresses written premision but we’re practically neighbors and he seemed like a real firnedly guy, didn’t even ask for anything in terms of if I find anything but I did offer to let him know if I find anything cool. Thoughts? Should I just send it?