He fought also with the king of the Ammonites, and prevailed against them,.... These were brought into subjection by David; but in later times endeavoured to cast off the yoke, and even invaded the land of Judah, as in the days of Jehoshaphat, and now in the reign of Jotham, but succeeded not, see Am 1:13and the children of Ammon gave him the same year one hundred talents of silver; he obliged them to pay this tribute annually, and which they began to pay in the present year, and amounted to 35,330 pounds,and ten thousand measures of wheat, and ten thousand of barley; the measure here is the "cor", the same with the "homer"; which, according to Godwin , held forty five gallons, or five bushels and five gallons, so that there must be upwards of 50,000 bushels of each of these paid to Jotham; according to Bishop Cumberland , a "cor", or "homer", held seventy five wine gallons, and upwards of five pints:so much did the children of Ammon pay both the second year and the third; the two following years as well as the present one; why this tribute was not continued to be paid cannot be said with certainty, whether the Ammonites refused and revolted, and could not be obliged, or whether the agreement was only for three years.
Moses & Aaron, l. 6. c. 9. Scripture Weights and Measures, ch. 3. p.