We have two sentences with the same words and actions in the past:
He had said that to me BEFORE I asked him. Here we have classical representation of Past Perfect by its rules. As I read here on site some answer that the word "before" is sufficient to show that the first action is " he says" and we can use simply Past Simple instead of Past Perfect it will be equally intelligible and we can say:
He had said that to me BEFORE I asked him. = He said that to me BEFORE I asked him.
But! Can it be possible that Past Perfect Tense may express UNFINISHED action that happened BEFORE the next action but was not finished? For example we say:
- He said that to me BEFORE I had asked him.
May it mean that I started asking him, maybe I opened my mouth and it was THE FIRST action and he, for example, understood "what" I was going to ask him and started "to say "that" to me"? So, that was the second action and we use in such cases or sentences exactly this arrangement of grammatical tenses, as was shown in the third example....