Who was first to say that it's good if a judge "keeps easy cases easy"?

We're very familiar with the old expression "Hard cases make bad law," from which one can infer that easy cases make good law and, perhaps, an idea that judges should make an effort to keep easy cases easy.

In today's case about drug-sniffing dogs, Justice Scalia said that using a property-rights analysis (rather than discussing the expectation of privacy) "keeps easy cases easy." Justice Kagan picked up the phrase in her concurring opinion to say that using both forms of analysis "would make an 'easy cas[e] easy' twice over."

Should we credit Justice Scalia with the new aphorism "kee[p] easy cases easy"? (Note that I'm using the Kagan approach to brackets as I drop the s on "keeps.")

The only near example I found in the state and federal courts database was Mozes v. Mozes, 239 F.3d 1067 (9th Cir. 2001), in which Judge Alex Kozinski said that something "illustrates that easy cases are easy, however one analyzes them." But that's not the same as proclaiming it a virtue to keep easy cases easy, so I give the aphorism to Justice Scalia.

By the way, Scalia loves to talk about easy cases. For example, last fall:

"The death penalty? Give me a break. It's easy. Abortion? Absolutely easy. Nobody ever thought the Constitution prevented restrictions on abortion. Homosexual sodomy? Come on. For 200 years, it was criminal in every state," Scalia said at the American Enterprise Institute.

Sometimes when one lawyer says a case is easy, you want to say — as I once heard Professor Henry Monaghan say — "Yes, but which way is it easy?"