Yeremia 46:20

46:20 Egypt is like a beautiful young cow.

But northern armies will attack her like swarms of stinging flies. ¹ 

Yeremia 1:15

1:15 For I will soon summon all the peoples of the kingdoms of the north,” says the Lord. “They will come and their kings will set up their thrones ²  near the entrances of the gates of Jerusalem. ³  They will attack all the walls surrounding it, and all the towns in Judah. ⁴ 

[46:20]  ¹ tn Heb “Egypt is a beautiful heifer. A gadfly from the north will come against her.”
The metaphors have been turned into similes for the sake of clarity. The exact meaning of the word translated “stinging fly” is uncertain due to the fact that it occurs nowhere else in Hebrew literature. For a discussion of the meaning of the word which probably refers to the “gadfly,” which bites and annoys livestock, see W. L. Holladay, Jeremiah (Hermeneia), 2:331, who also suggests, probably correctly, that the word is a collective referring to swarms of such insects (cf. the singular אַרְבֶּה [’arbeh] in v. 23 which always refers to swarms of locusts). The translation presupposes the emendation of the second בָּא (ba’) to בָּהּ (bah) with a number of Hebrew mss and a number of the versions (cf. BHS, fn b).

[1:15]  ² tn Heb “they will each set up.” The pronoun “they” refers back to the “kingdoms” in the preceding sentence. However, kingdoms do not sit on thrones; their kings do. This is an example of a figure of speech called metonymy where the kingdom is put for its king. For a similar use see 2 Chr 12:8.

[1:15]  ³ map For location see Map5 B1; Map6 F3; Map7 E2; Map8 F2; Map10 B3; JP1 F4; JP2 F4; JP3 F4; JP4 F4.

[1:15]  ⁴ tn Or “They will come and set up their thrones in the entrances of the gates of Jerusalem. They will destroy all the walls surrounding it and also destroy all the towns in Judah.” The text of v. 15b reads in Hebrew, “they will each set up his throne [near? in?] the entrance of the gates of Jerusalem and against all its walls…and against all the towns….” Commentators are divided over whether the passage refers to the kings setting up their thrones after victory in preparation for passing judgment on their defeated enemies in the city or whether it refers to setting up siege against it. There is no Hebrew preposition before the word for “the entrance” so that it could be “in” (which would imply victory) or “at/near” (which would imply siege), and the same verb + object (i.e., “they will set up their thrones”) governs all the locative statements. It is most often taken to refer to the aftermath of victory because of the supposed parallel in Jer 43:8-13 and the supposed fulfillment in Jer 39:3. Though this may fit well with the first part of the compound expression, it does not fit well with the latter part which is most naturally taken to refer to hostile attacks against Jerusalem and the other cities of Judah. The translation given in the text is intended to reflect the idea of an army setting up for siege. The alternate translation is intended to reflect the other view.