Matthew 20:2

A penny - A Roman coin, as noted before, Matthew 18:28, worth about seven-pence halfpenny or seven-pence three farthings of our money, and equal to the Greek drachma. This appears to have been the ordinary price of a day's labor at that time. See Tobit 5:14. In 1351 the price of labor was regulated in this country by parliament; and it is remarkable that "corn-weeders and hay-makers, without meat, drink, or other courtesy demanded," were to have one penny per day! In 1314 the pay of a chaplain to the Scotch bishops, who were then prisoners in England, was three halfpence per day. See Fleetwood's Chronicon Precios, p. 123, 129. This was miserable wages, though things at that time were so cheap that twenty-four eggs were sold for a penny, p. 72; a pair of shoes for four-pence, p. 71; a fat goose for two-pence halfpenny, p. 72; a hen for a penny, p. 72; eight bushels of wheat for two shillings, and a fat ox for six shillings and eight-pence! Ibid. In 1336, wheat per quarter, 2s.; a fat sheep 6d.; fat goose, 2d. and a pig, 1d., p. 75.

A penny a day - The coin here referred to was a Roman coin, equal in value, at different periods, to 15 cents or 17 cents (7 1/2 d. to 8 1/2 d.) (circa 1880's). The original denotes the Roman denarius δηνάριον dēnarion, a silver coin, which was originally equivalent to ten ases (a brass Roman coin), from which it gets its name. The consular denarius bore on one side a head of Rome, and an X or a star, to denote the value in ases, and a chariot with either two or four horses. At a later period the casts of different deities were on the obverse, and these were finally superseded by the heads of the Caesars. Many specimens of this coin have been preserved.

It was probably at that time the price of a day's labor. See Tobit 5:14. This was the common wages of a Roman soldier. In England, before the discovery of the mines of gold and silver in South America, and consequently before money was plenty, the price of labor was about in proportion. In 1351 the price of labor was regulated by law, and was a penny a day; but provisions were of course proportionally cheap, and the avails of a man's labor in articles of food were nearly as much as they are now.

20:2 The Roman penny was about seven pence halfpenny. [About thirteen and three quarter cents, American.] This was then the usual price of a day's labour.