Be-REiShYT (In-the-beginning) is composed of the letters ShYR (Song-of) TAeV (Desire), and this is the most praiseworthy song of all songs, desired above all songs, and upon it is stated: (Song. 1:1) A song of songs which is to Solomon (Shlomoh), ‘the King to whom peace (shalom) belongs’xxxiiMidrash Rabbah Shir HaShirim 1:12, thus they the sages have established.
And when will this ‘song’ be aroused? When they are vanquished – Samael and his wicked agents – from the world. And at that time: [song] (Ex. 15:1) Then (az) Moses sang... It is not written ‘then he sang (shar)’ but he will sing (yashirxxxiiiBT) Sanhedrin 91b, and they the sages have established this.