Joel 2:30-31

The signs of approaching judgement which will then appear.

shew lit. give, as Exodus 7:9; Deuteronomy 6:22.

wonders better (for the word used has no connexion with those commonly rendered wonderful, wondrous) portents, extraordinary phenomena natural, or supernatural, as the case might be arresting attention: see e.g. Exodus 4:21; Exodus 7:9; Isaiah 8:18; Ezekiel 12:11.

blood and fire i.e. either, as some suppose, wars on an unprecedented scale (-portents in the earth"), or more probably (as wars are not suggested by the context), abnormal atmospherical phenomena (cf. Joel 2:31).

pillars of smoke Song of Solomon 3:6, of the smoke of incense, heralding a procession (the word rendered pillarsoccurs only in these two passages). Possibly of the columns of smoke rising up from burnt cities (Judges 20:38; Judges 20:40; cf. Isaiah 9:18); more probably (Thomson, The Land and the Book, Southern Pal., p. 142) with allusion to columns of sand and dust raised high in the air by local whirlwinds accompanying a sirocco, which sometimes "march with great rapidity over the open plain, and closely resemble -pillars of smoke"."