Green’s Dictionary of Slang

to mumble one’s prayers speedily and with no interest in their meaning.

1725		New Canting Dict. n.p.: To chop is also used to make Dispatch, to slubber over in Post-haste, as, The Autem-Bawler, will soon quit the Hums, for he chops up the Whiners; i.e. The Parson will soon have dispatch’d the Congregation, for he huddles over the Prayers; used by such as wait till Divine Service is over, to pick Pockets, &c.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: To chop, in the canting sense, means making dispatch, or hurrying over any business: ex. The autem bawler will soon quit the hums, for he chops up the whiners; the parson will soon quit the pulpit, for he hurries over the prayers.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1828		Lytton Pelham III 292: Did not I tell you I should bring a pater cove, to chop up the whiners for Dawson?
1830		Lytton Paul Clifford I 3: I vent first to Mother Bussblone’s, who, I knows, chops the whiners morning and evening to the young ladies, and I axes there for a Bible.
1857		‘Dear Bill, This Stone-Jug’ Punch 31 Jan. n.p.: For them coves in Guildhall, and that blessed Lord Mayor, / Prigs on their four bones should chop whiners I swear.