The caption has the Jewish man saying "Oh Lord, let me die (as a result) of a stroke, and not (as a result) of an ax" - which rhymes in Arabic.
The second commenter, Mohammed Abu Amra, said "Amen" and added other methods to kill Jews.
Abu Amra says that he works for UNRWA as well as a technology education manager. He also posted a photo of a young girl with an automatic weapon with the caption "Everything in Gaza is beautiful."
Does UNRWA condone its teachers laughing about the murder of rabbis? Based on their lack of action from the other disgusting Facebook posts I have uncovered, one can only conclude that the answer is "yes."
And their claims to take these charges seriously is nothing but a smokescreen for their underlying antisemitism.
(h.t Ibn Boutros)