LEFT HORN = BLOWN AT MOUNT SINAI RIGHT HORN = BLOWN FOR THE MESSIANIC REDEMPTION

The ram of Isaac which was caught in the thicket and sacrificed in place of Isaac had two horns. The God of Israel blew upon the left horn on Mount Sinai when the Torah was revealed.

The right horn was greater than the left one. In the future, the God of Israel will blow upon it when He brings back the exiles to the land of Israel. (Pirkei d'Rabbi Eliezer Chapter 31)