Unidentified Song

The movie has extensive ending credits, but I could not find the answer to this question.

About a quarter of the way into the film, there is a moment where a man stands up and sings. The song would appear to be from the 1940s and seems to relate to the founding of Israel.

The man starts with the line, Now that those in Palestine no longer are depressed. Then says Sing Israel, sing Israel. And later, Now that you are free, yearn no more D P.

Does anyone know the name of the song and the man who is singing it?

Thanks for any help.