 After serving as rabbi in Ryczywół and Shineva, Horowitz was invited, in 1773, to become the rabbi of Nikolsburg in Moravia, where he served until 1778.On the first day of his being rabbi of Nikolsburg, Abraham Trebitsch, a native of Nikolsburg, reported him performing a miracle and bringing rain.It is told that his strong attachment to hassidism angered many members of the community, which led to bitter quarrels that were quelled as a result of the personal intervention of Elimelech of Lizhensk.