The phrase "say of that" is correct and usable in written English.
It is usually used as an idiomatic expression that means to make a statement about a particular situation. For example, "I don't know what to do, but what can I say of that?".
And what to say of that stage set of red and gold drapings out of Cecil B. DeMille?
It wasn't long ago she was attacking a toilet attendant.' "I was slightly depressed by how people say of that attack, 'Oh, it was a long time ago.
Afterward, my father would say of that day that walking away from that drunken son of a bitch with a rifle in his hands was about the hardest thing he'd ever done.
Above all, remember Walsh for being a man who reported for work in a wheelchair day after day after surgery on his neck, who put up with Dolan's attempt to rehire Thomas, and who would say of that sad episode only that it was annoying because of "the attention it generated".
Tagore's first name sounded like gobbledegook to Larkin's ears, and Dickens, who met Tagore's grandfather Dwarkanath in London in 1842, had this to say of that name: "I have spelt it backwards, but it makes no less tremendous nonsense that way".
The first point to make is that, for this feature-length version at any rate, anyone expecting a brisk, informative science lesson – along the lines, say, of that rather handy little film that explained how they cloned dinosaurs in Jurassic Park – will be disappointed.
I know a lot has been said of that".
"It was turbulent, literally," he said of that first project.
"It was so hard," Ms. Gottfried said of that controversy.
"We locked eyes," he said of that night in April 2006.
"Microfinance is basically poverty management," he said of that tactic.
