A gentleman and I had a verbal agreement to purchase a mobile home?
As Kathie said, if you are an honorable person, you will give them back their down payment. Now, on a practical matter, give them their down payment back, because, if you do not, they could sue you for the money, tying up your mobile home and making it difficult to sell. If they really wanted to be vindictive, they could put a lien on the mobile home, and it might cost you ten times the amount of the down payment. Give it back, get a receipt stating that he received it in full, and move on.