I'm wondering the following conversations, extracted mostly from a comedic video at the following timestamps links: a,In this one it says you walk, no you say, but it's similar concept,c. The phrases go like this, I'm interested in what "you say" means. I think it means the speaker disbelieves the claim made by the other person.
Example 1: -Sorry I can't party I'm busy -You say you're busy
(He thinks it's not busy, but making up an excuse).
-I couldn't wash the car, I have hand pain. -You say you have hand pain.
(He thinks he was lazy or something else, not that he has hand pain, that's he thinks it's just an excuse)
I've seen this question but it says "You say that" as a phrase. I want to know if this is analogous, and if you can point me to some link or reference where it's being used.