1. He said, "It is going to rain". (If reported in print); If reported in speech, as in your post #1, ("said", a minute ago, yesterday, last week etc.; "is going to", a prediction)
2. He said it was going to rain. A. "Look, it's sunny" B. "Yeah, I know, the weatherman said it was going to rain today."
Why is 1 correct? I think 2 is grammatical because he "said" not "says".
Thank you.