Ok so he's being shipped to me from Thailand

I am setting up a brand new tank...and plan on cycling that tank with a guppy. In the mean time...I have a 1 gallon goldfish bowl for my new betta to live in (I don't want to hurt him with the ammonia cycling process). Would it be safe/good for him to take a gallon of water from my boyfriend's mother's 5 year old tank and put that in his fish bowl to live in while his big 10 gallon cycles? Thanks everyone!