"Wow, I don't think that I have the authority to order that" - said no fed ever.
Grover Cleveland came close when he said this in 1986:
"I feel obliged to withhold my approval of the plan, as proposed by this bill, to indulge a benevolent and charitable sentiment through the appropriation of public funds for that purpose.
I can find no warrant for such an appropriation in the Constitution, and I do not believe that the power and duty of the General Government ought to be extended to the relief of individual suffering which is in no manner properly related to the public service or benefit. A prevalent tendency to disregard the limited mission of this power and duty should, I think, be steadfastly resisted, to the end that the lesson should be constantly enforced that though the people support the Government the Government should not support the people. "
He might have been the very last honest Democrat ever to hold office.