Do you say, "I passed by a man whose two parents are standing," or "whose parent is standing"?

The questioner : Do you say: "I passed by a man whose two parents are standing," or "whose parent is standing"?

The Shaykh : "Whose parent is standing," "whose parent is standing," except in the dialect of the fleas.

The questioner : No, we said: "Two standing"!

The Shaykh : Huh?

The questioner : "Two standing," because it follows "man."

The Shaykh : Yes, it follows.

The questioner : In terms of grammatical case.

The Shaykh : Yes, but you do not use the dual form; you do not use the dual marker, because if the subject is feminine, what is required in the verb? If the subject is dual, what is required in the verb?!
It is like the verb; if it is dual, the requirement in the verb is the base form; you do not use the dual marker, or do you? Is that clear?

The questioner : Yes.

The Shaykh : All right: Say, "His parents stood up" or "His two parents stood up"?

The questioner : "His parents stood up."

The Shaykh : Without the alif?

The questioner : Yes, I do.

The Shaykh : All right, this is the same thing.

The questioner : We said: It follows what comes after it in the singular, dual, and plural, if it is a relative pronoun.

The Shaykh : What comes after it! Yes, but like the verb, we linked it to the verb, and it follows what comes after it in terms of masculine and feminine only, in any case; as for the singular, dual, and plural, it is like the verb. Yes, is it clear now?

The questioner : Yes.

The Shaykh : Good.