This is the transcript at the link, about 16:20 mark. I don't know what the OP was concerned about from this.
https://www.c-span.org/video/?471675-1/supreme-court-oral-argument-congressional-subpoenas-president-trumps-financial-records
PARDON, SIR. NOT PRESIDENTIAL FINANCES, WE ARE ASKING FOR HIS PERSONAL TAX RETURNS BEFORE HE BECAME PRESIDENT. THOSE ARE VERY DIFFERENT THINGS. AND WE ARE NOT ASKING HIM TO PRODUCE IT. SOME OF THE SUBPOENAS AS FAR BACK AS 1792 HAVE ASKED FOR PERSONAL PAPERS OF THE PRESIDENT WHILE BEING PRESIDENT. THIS IS BEFORE HE WAS PRESIDENT. I DON'T UNDERSTAND. AND THEY ARE NOT HIS PAPERS IN THE SENSE OF HE'S NOT IN POSSESSION OF THEM. THESE ARE SUBPOENAS TO PRIVATE ENTITIES.