Jeremiah 32:15 - Matthew Poole's English Annotations on the Holy Bible

Here is nothing of any seeming difficulty in these verses, but only why the prophet commandeth Baruch to put the evidences in an earthen vessel, which himself also expounds, that they might continue many days, that is, not defaced: had they been hid many days in the earth, they would have been rotten; had they been above ground in a box or chest, they might have been lost, or taken away by the soldiers plundering houses, or at least burnt with fire. Jeremiah 32:15, the prophet expounds God's meaning in this command to him, and his own design, in so formal a buying of so small a purchase, especially considering, that, very probably, Jeremiah was no great purchaser, nor very greedy of purchases. He lets them know that all this was for a sign of the truth of what God had revealed to him concerning the people's return, though after many days, (sixty years from this time,) and also of the firm assent he gave to that Divine revelation, that purchases should one day be enjoyed again in Judea, and houses, fields, and vineyards in it should be again possessed.