Green’s Dictionary of Slang

rocked in a stone kitchen phr.

foolish, stupid.

c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Rock’d He was rocked in a Stone Kitchen; a Saying meant to convey the Idea that the person spoken of is a fool, his Brains having been Jumbled by the Shakes given to his cradle.
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn) n.p.: He was rocked in a stone kitchen; a saying meant to convey the idea that the person spoken of is a fool, his brains having been disordered by the jumbling of his cradle.
1811		Lex. Balatronicum [as cit. 1788].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
[1859		Matsell Vocabulum 74: rocked in a stone cradle Born in a prison].