This reminds me of one of the old Charlie Brown cartoons, and a conversation between Linus and Lucy.
(I'm paraphrasing here)
LUCY: You have to get me a present! The Bible says so!
LINUS: Show me in the Bible where it says that.
(Lucy leafs through the Bible)
LUCY: Ah, here it is!
LINUS: That's just the word "sister."
LUCY: Yeah, and that means you have to get your sister a present!
LINUS: Good grief.