I believe with complete faith
In the coming of the Messiah,
And even though he may tarry,
I will wait for him, whenever he comes.

The above verse is taken from the text of “Ani Ma’amin”, a popular rendition of the thirteen principles of Jewish faith as elaborated by Maimonides (1138-1204) in his commentary on the Mishnah in tractate Sanhedrin. Many Jews recite the thirteen principles of faith during their morning prayers.
The twelfth principle, the belief of the coming of the messiah, has often been popularized in song and prayer. Reb Azriel David Fastag, a Modzitzer Chassid, reportedly penned one version of the song while being deported in a cattle car to the Treblinka death camp. The tune was then sung by other Jews during the Holocaust, and is often part of memorial ceremonies for the victims of the Holocaust.