Why does Jeremiah suddenly curse the day of his birth?

This passage of lament (Jeremiah 20:14–18) follows directly after the lament in Jeremiah 20:7–13. There is, however, a wild and extreme change in mood as Jeremiah goes from singing the Lord’s praises in Jeremiah 20:13 to effectively describing his birth, and his prophetic ministry, as a curse.  In these verses (Jeremiah 20:14–18) Jeremiah plumbed the depths of bitterness and despair, revealing a depth of misery and agony surpassing any other cry of anguish recorded among his lamentations.¹ The reader is left to grapple with this sudden swing in mood. Did Jeremiah really experience these dark feelings directly after the praises of Jeremiah 20:13? Or do these two laments come from completely different times in his ministry, but are brought together here to make a point? These questions cannot be answered decisively from the text and so the only certainty the reader is left with is the fact that these two passages have been placed where they are. Rather than analyze too critically the existence of such extremes in mood, the reader should learn from the entire passage as it stands. Those who have never been through an experience like that of the prophet are best advised to stand in silent sympathy rather than act as armchair critics of the sorely tested.²

The other purpose that Jeremiah 20:7–18 serves is as a transition to Jeremiah 21:1–24:10 which are a collection of judgment speeches against Judah. So, this passage forms a transition from Jeremiah’s personal experience (Jeremiah 19:1–20:18) to the collective experience of the nation (Jeremiah 21:1–24:10) in which the prophet was involved.³

The lament in Jeremiah 20:14–18 begins with Jeremiah describing the day of his birth as cursed. It is possible to translate the Hebrew text in a way that has Jeremiah not simply wishing that his birth be cursed but stating that the day of his birth was cursed because of his birth.⁴ This indicates the real depth of despair and misery Jeremiah is feeling. Jewish law forbade cursing the Lord or your parents (Leviticus 20:9; Leviticus 24:10–16). Jeremiah avoids doing both and rather curses his birth. However, by describing his birth as a curse, Jeremiah is also describing his prophetic calling by the Lord since the Lord called Jeremiah before he was born (Jeremiah 1:5).⁵