Note E72 — 16.
Reading edition
"Buieng or selling of pig in a poke," i.e. making a blind bargain.
"A good cochnay coke, Though ye loue not to bye the pyg in the poke, Yet snatche ye at the poke, that the pyg is in, Not for the poke, but the pyg good chepe to wyn." —Heywood's Dialogue (1546), ed. 1562, part ii. cap. 9.
See also Hazlitt's Handbook of English Proverbs, p. 413.