God Says: I will return from Bushan, I will return from the depths of the ocean

This is a verse in Psalms (Tehilim 68). The Medrish relates how the children taken into captivity for p. by the Romans learned from this verse that even if they would throw themselves into the depths of the sea, God would ultimately resurrect them. This is a lesson Rabbi Nachman wanted to instill in the world.

The word BuShaN is the acronym: [Rabbi] Nachman Ben (son of) Simcha! The word Usheev - I will return - is the acronym: Yisroel Ber (son of) Eizik Shlomo - Saba Yisroel!

Aleph Samech added that the word Usheev - I will return - which is the acronym of Saba's name, is also the acronym for the famous words of Rabbainu: Ain Shum Yeiush BuOlam - There is utterly no despair in the world!