Go thou, and read. Since Jeremiah was restricted from going “into the house of the Lord,” Baruch was called upon not only to be the prophet’s secretary but also to be the preacher of Jeremiah’s divinely inspired messages.
Upon the fasting day. This occasion was not a regular yearly fast (see on v. 9), but one of those special occasions “proclaimed” in time of national crisis (2 Chron. 20:1-3; Joel 2:15). It was a time when a large number of people would be gathered together, and be in a frame of mind to listen to a divine admonition and an appeal for repentance. It is possible that Jehoiakim, on the advice of his apostate priests and false prophets, called this fast to arouse the people to greater resistance against the Babylonians.