He's aye wise ahint the hand.

"Ye noo hae hit the nail upo' the head,
I better wi' less travel micht hae deen,
Had I been tenty as I sud hae been;
But fouks, they say, are wise ahint the han',
Whilk to be true unto my cost I fan."

—Ross's Helenore.

He's as wise as Wudsie's calf, that kent milk frae water.

He's been at the kirk o' Crackabout, whaur the kail pat was the minister.

He's better fed than bred.

He's blind that eats marrow, but far blinder that lets him.

He's but Jock the laird's brither.

"The Scottish lairds concern and zeal for the standing and continuance of their families, makes the provision for their younger sons very small."—Kelly.

He's cooling and supping.