{N}2,{/}12: {C}Return to me with your whole heart: {/}an invitation to penance. In times of hardship, public fasts were proclaimed in Israel. People would wear mourning clothes, or they would replace their clothes with sackcloth, or they would not comb their hair and cover their faces with ashes. In the Gospel, Jesus will not say that these signs of physical penance, like fasting to express sorrow and to accompany prayer, are useless (see Mt 4:1 and Mk 2:20), but will make it clear that these external signs of penance are not everything, nor are they what is most important.

{N}3,{/}1: Joel announces the {C}Day of Yahweh,{/} a term indicating God's coming Judgment, and the salvation of the elect, at the same time.
{C}I will pour out my Spirit on every mortal. {/}Already in the days of the Old Testament God communicated his Spirit to the prophets and to saviors (see Is 11:1 and Jdg 11:1). Here, however, it is a decisive sign that the Spirit will be given to all believers. {C}They will dream dreams and see visions. {/}In those remote days, such were normal means of prophetic communication. Through these words Joel announces what Isaiah did when he said: {C}All your children will be taught by God {/}(Is 54:13 and Jer 31:31).
{C}I will show wonders in the heavens. {/}The wave of prophesy will accompany many signs indicating a grave crisis in the world. The image of the {C}sun turning to darkness {/}expresses both chaos in nature and impossible situations in the life of humankind.
{C}Then all... will be saved. {/}This will be a time when people will not be able to avoid a decisive choice: to retain their former lifestyles or to invoke the {C}name of Yahweh {/}which means to surrender their lives and hopes to him and rely on his powerful intervention.
It seems that these three factors were present for the Jewish people in the years following the resurrection of Jesus and before the destruction of the nation. Peter quotes this text on the day of Pentecost (Acts 2:17). In these last years of the 20th century, many events can be interpreted the same way.

{N}4,{/}1: We can apply to this chapter what is said concerning Zechariah 12-14. The prophet uses a crisis in which the Jews were harshly oppressed to emphasize that God is the Lord of history.

