John Calvin's Bible Commentary
Jeremiah 27:4
Though the Prophet was bidden to command the ambassadors to say to the kings by whom they had been sent, Thus saith Jehovah, of hosts, (178) they yet might have refused to do so, and that with indignation: “What! Are we come here to be ambassadors to thee? and who indeed art thou who commandest us? besides, dost thou think that we are so mad as to threaten for thy sake, our kings and masters, and to declare to them what thou biddest, that they are shortly to become the servants of the Chaldean king?” The ambassadors then might have thus treated the holy Prophet with derision and laughter: but, as we have said, the whole was done for the sake of Zedekiah and the people, in order that the Prophet might dissipate that vain splendor and pomp, by which he saw that Zedekiah and all the Jews were deceived; for they thought that they had as it were high and large mountains to be set in opposition to the Chaldean king and his army: “On what part can they assail us, since the king of Tyrus is on our side, and also the king of Sidon, the king of Moab, and the king of Ammon? these rule widely, and their cities are impregnable.” Thus, then, the Jews were convinced that they would be exempt from every trouble and molestation; but in order that they might not deceive themselves with that vain display, Jeremiah said,
“Declare, ye ambassadors, to your masters what God has spoken, even that ye must submit to the yoke of the king of Babylon.”
And a visible symbol was added in order to confirm the prediction: the Prophet was bidden to put a yoke on his neck, or yokes, for he speaks in the plural number. מוט muth, means a pole, a yoke, a transverse piece of wood: and no doubt he applied some pieces of wood to his neck, like the yoke laid on oxen; and then he tied this yoke or crossbar; for יסר, isar, means to bind or tie, and so מוסרות, musarut, are bands; מוסר, musar, also means sometimes a girdle; but here it is to be taken for bands or ligaments. It was a sad spectacle to see on the neck of Jeremiah, when he went forth, the symbol of the bondage of all kings and nations: he was as it were in the place of all a captive before the time: but when God laid a yoke on the Jews and on all other nations, Jeremiah was then a free man; for though he bore this mark of bondage, he yet expected God’s judgment with a resigned mind, while others disregarded it. But this confirmation rendered them more inexcusable, as the case is, when God, to strengthen faith, adds sacraments or other helps to his word, by which means he impresses us the more, for he thus teaches not only our ears, but also our eyes and all our senses: when God thus omits nothing that may tend to strengthen our faith in his word, a heavier condemnation awaits us, if such signs avail not.
We then perceive the reason why the Prophet applied to his neck the symbol of future bondage: were there any teachable among the people, to see such a sign with their eyes must have been useful to them. But as the greater part had hardened themselves in their obstinacy, what ought to have done them good, by humbling them in time before God, so as to anticipate his judgment, had no other effect but to render their punishment more grievous.