Dear _______________,
We were delighted that you attended our wedding. Thank you so much for sharing our big day, excitement and happiness! We’d also like to thank you for your very generous wedding gift of cash. There are not enough words to thank you for your kindness. We plan to use this gift of money as part of a down-payment on a condo we are purchasing. Your thoughtfulness will always be remembered.
With love and affection,
(YOUR NAME HERE)