Литература Второго Храма к Шмот 28:31

וְעָשִׂ֛יתָ אֶת־מְעִ֥יל הָאֵפ֖וֹד כְּלִ֥יל תְּכֵֽלֶת׃

И сделай халат эфода синим.

On the Migration of Abraham

[104] And he has well weighed his words when he adds: “His sound shall be audible when he is about to enter into the Holy Place” (Ex. 28:31), to the end that when the soul is about to enter the truly holy place, the divine place which only mind can apprehend, the senses also may be aided to join in the hymn with their best, and that our whole composite being, like a full choir all in tune, may chant together one harmonious strain rising from varied voices blending one with another; the thoughts of the mind inspiring the keynotes—for the leaders of this choir are the truths perceived by mind alone—while the objects of sense-perception, which resemble the individual members of the choir, chime in with their accordant tuneful notes.