some good advice to not start out on edibles if he has never toked before (or if its been a long time). plus rep for those of you. Start out small to give him the feel
. Be there with him to reassure him and make him feel comfortable. Stay with him while he does it for the first few times and talk to him during the "session". Tripping on marijuana
by yourself when you are potentially terminally ill is not a good idea. The mind can run to new places, places that were maybe ignored before Marijuana "expanded" it.
Just monitor him closely until you know he is good with it. Believe it or not but some people (not many that I know) have tried marijuana and not enjoyed it and it is usually due to their first experience.