Joel 2:30

And I will show wonders in the heavens and in the earth
This, and what follow, refer to the prodigies seen in the air, and done in the earth, a little before the destruction of Jerusalem ^F18; when in the air were seen comets and blazing stars, particularly one in the form of a sword, hanging over Jerusalem, and appearances of armies engaged in battle; and, on the earth, a flame was seen in the temple, and a voice heard in it, saying, let us go hence; the doors of it opened of themselves; an idiot went about, crying woe to the people, woe to the city blood, and fire, and pillars of smoke;
"blood" may design the great slaughter of then by the Roman army in the land of Judea, and by murders committed among themselves in the city of Jerusalem, which were very horrible, and of great numbers; "fire", the burning of towns and cities; though Kimchi interprets it of lightnings in the heavens; and "pillars of smoke", rising up in straightness and height like palm trees, as the word ^F19 signifies, vast quantities of it arising from cities and towns burnt. Gussetius ^F20 interprets this of the burning of the martyrs in the first ages of Christianity, and of their spiritual affections, which ascended upwards to God, and were grateful to him; see ( Song of Solomon 3:6 ) .