The quote I was thinking of was made by Longstreet (according to Sears, "Gettysburg," p.357). On the morning of July 3, 1864 Longstreet said to General Lee, "General, I have been a soldier all my life. I have been with soldiers engaged in fights by couples, by squads, companies, regiments, divisions, and armies, and should know, as well as any one, what soldiers can do. It is my opinion that no fifteen thousand men ever arrayed for battle can take that position." Then he pointed to Cemetery Hill.