I’m writing a short prose piece for an academic audience and need to know whether the following sentence sounds right, especially its first clause:
What he had just said, especially that final sentence, really enlightened me.
The context here is that I’m recounting a story in the past where person A has just told me something interesting, and the quoted sentence describes its effect on me.
I do believe the use of had in the sentence above is correct. Could anyone explain why is it correct if it is, or if it is not, then why it does not sound right to use this way?