Precipitate, passionate. He is none of the Hastings sort; a saying of a slow, loitering fellow: an allusion to the Hastings pea, which is the first in season.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Hash * Hasty PuddingNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes