Deuteronomy 11:29

The blessing... and the curse... — The Targum of Onkelos says, “Those that bless,” and “those that curse.” (See Deuteronomy 27:12, and Note.[1])

[1] The other Targums say, “When they bless they shall turn their faces towards Mount Gerizim; and when they curse they shall turn their faces towards Mount Ebal.” This confirms the antiquity of the view taken in the Talmud.