Jeremiah 32:9 - Joseph Benson’s Commentary on the Old and New Testaments

I weighed him the money In ancient times all money was paid by weight, a custom still used in several countries; even seventeen shekels of silver A sum which, in our money, is not much above forty shillings; a small price for a field or piece of ground. It must be considered, however, “that the quantity of land is uncertain, and that the circumstances of the times must have greatly tended to lessen the value of land. The field in question was at the time of the purchase in the enemy's possession; and the purchaser well knew that he or his heirs had no chance of entering upon it till after the expiration of the seventy years' captivity. Besides, the seller, it is likely, was in the immediate want of the money, and could get no one else to purchase in the precarious situation things were in. He might therefore be glad to take what the prophet, who, doubtless, was not rich, was able to give, and who would not have thought of making the purchase at any rate had he not acted under the divine direction for a special purpose.” Blaney.