One should direct one’s heart in prayer toward the Holy of Holies.
Toward which Holy of Holies?
Rabbi Hiyya said: Toward the heavenly Holy of Holies.
Rabbi Shimon ben Halafta said: Toward the earthly Holy of Holies [i.e., the innermost part of the Temple in Jerusalem].
Rabbi Pinhas said: There is no disagreement here. The earthy Holy of Holies is directly opposite the heavenly one.
Jerusalem Talmud, Berakhot 4:5