2 U.S. Code § 1866
2 U.S. Code § 1866 is about Certification of vouchers. It is under Subchapter IV (Appropriations and Expenditures) of Chapter 28 (Architect of the Capitol) of Title 2 (The Congress) of the Code.
It shall not be a duty of the Architect of the Capitol to certify any pay roll or other voucher covering any expenditure from any appropriation for the Senate Office Building, or for any other building or activity, unless the obligation involved was incurred by him or under his direction.