In any situation you either have permission or you don't, and you may not have authority to tell someone else that they can also hunt the land. Your friend, or anybody else needs to have written permisssion showing they have permission to hunt and what the limitations of that permissison are: is is exclusive to the one hunter, can they carry others on the property, etc. It is best to have an exclusive lease with all hunting rights. Your question is a little vague as to if he has lawful permission to hunt the land..