7 of the U.S. Constitution. I have read a wide variety of cases on this point. In fact, the brief from which I extracted the material on my web site merely cited 45 cases to support my proposition. Your inability to read and understand cases is shown via your note. For example, you mention the Costle case which I use in my brief.
Appropriations permit an agency to incur obligations and to make payments on obligations.
Contract authority is legislative authorization for an agency to create obligations in advance of an appropriation. It requires a subsequent appropriation or some other source of funds before the obligation incurred may actually be liquidated by the outlay of monies. Borrowing authority permits an agency to spend debt receipts. This is just one of many cases on the point and if you wish to read more, I simply direct you to the file posted at my site. Get the cites and then go read the cases.