i. e. he goes a-straying, or goes astray.
The explanation of this construction I take to be this; the -ed was not really a sign of the past participle, but a corruption of the ending -eth (A. S.-að) which is sometimes found at the end of a verbal substantive. Hence it is that, in the passage from Piers Plowman above quoted, one of the best and earliest MSS. actually reads 'folk that gon a-beggeth.' And again, in another passage (P. Pl., C. ix. 246) is the phrase 'gon abrybeth,' or, in some MSS., 'gon abrybed,' i. e. go a-bribing or go a-thieving, since Mid. Eng. briben often means to rob. This form is clearly an imitation of the form a-hunteth in the old phrase gon a-hunteth or riden an honteth, used by Robert of Gloucester (Specimens of English, ed. Morris and Skeat, p. 14, l. 387):—
'As he rod an honteth, and par-auntre [h]is hors spurnde.'
Now this honteth is the dat. case of a substantive, viz. of the A. S. huntað or huntoð. This substantive would easily be mistaken for a part of a verb, and, particularly, for the past participle of a verb; just as many people at this day are quite unable to distinguish between the true verbal substantive and the present participle in -ing. This mistake once established, the ending -ed would be freely used after the verbs go or ride. In D. 1778, we even find go walked, without a.
The result is that the present phrase, hitherto so puzzling, is a mere variation of 'gon a blake-berying,' i. e. 'go a-gathering blackberries,' a humorous expression for 'wander wherever they please.' A not very
dissimilar expression occurs in the proverbial saying—'his wits are gone a-wool-gathering.'
The Pardoner says, in effect, 'I promise them full absolution; however, when they die and are buried, it matters little to me in what direction their souls go.'
407. Tyrwhitt aptly adduces a parallel passage from the Romaunt of the Rose, l. 5763 (or l. 5129 in the French)—
'For oft good predicacioun
Cometh of evel entencioun.'