I wonder if Bob even convinced John to rewrite it....... remember they were having a little disagreement about it and Bobby said something like "I'll hassle him about this later" because when he first mentioned rewriting it John was like "Well I don't know, a lot of people like that song"
I wonder if John could of convinced him to sing it without rewriting ? - It didn't really seem like Bobby wanted to sing it in its original lyrics....
to understand why you have to read the lyrics a little deeper, think about the context of the song, think about the time and era it was performed
esau had different lyrics on many occasions
its one that bob obviously never felt he quite got right