Even in Old English times, on was sometimes reduced in compound words like abūtan (now about), a variant of on būtan ‘on the outside of.’ The reduced form appears in early Modern English aboard, afield, abed, and asleep, and with verbal nouns in -ing (a-hunting, a-bleeding, a-praying). The a of “twice a day” and other such expressions has the same origin. In was sometimes contracted to i’, as in Shakespeare’s “i’ the head,” “i’ God’s name,” and so forth. This particular contrac- tion was much later fondly affected by Robert Browning, who doubtless thought it singularly archaic—for example, “would not sink i’ the scale” and “This rage was right i’ the main” (“Rabbi Ben Ezra”).