The variant on this joke I heard was that he wanted his wife to put all his money in his coffin with him. She readily agreed that she would do this, and he was happy.

Later when she was asked if she really did it, she said "Of course! It's what he wanted and as his wife I always did as I was asked. But, you know, I'm old, and that much money was more than I could carry. So I wrote him a cheque."