The Targum (Aramaic translation and interpretation) of the Song of Solomon begins with an enumeration of ten songs that are mentioned in the Torah.  It then writes that the tenth song will be sung by the Jews when they leave the exile.  The Targum quotes this verse:  “This song shall be to you as the night of the sanctification of the festival, and the joy of heart like one who goes with a flute to come upon the mountain of the Lord, to the Rock of Israel.”  The Targum interprets this verse to mean that when the Jews leave exile, they will sing a song accompanied by musical instruments.

In the mystical writings of Shaloh, he quotes the words of our sages, that “in the future the Jewish People will sing praises… in merit of Abraham who believed in G-d.”  The Shaloh asks:  What is the connection between the song of the future and the faith of Abraham?  The Shaloh explains that our sages were referring not only to the song of the Redemption, but to the songs that we will sing even before Moshiach comes, out of firm faith and joy in the prophecy of redemption. 

In the words of the Shaloh: “It is the nature of the righteous, that as soon as they are promised something good, they praise G-d immediately, even before it is fulfilled. This is because of their great faith… In the future, when the Jewish People will be foretold of the Redemption, they will rejoice and sing immediately, out of full faith that the prophecy will be fulfilled.”

Isaiah 26:19. Targum Shir Hashirim. Shemot Rabbah, 23:6. Shaloh, Torah Shebichtav, Parshat Beshalach. See also Torat Menachem 5748, vol. 4, p. 268. 5752, vol. 2, p. 176.