He is as like his father as if he was spit out of his mouth; said of a child much resembling his father.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Spiritual Flesh Broker * Spit-1Nathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes