וְשַׂמְתֶּם֙ אֶת־דְּבָרַ֣י אֵ֔לֶּה עַל־לְבַבְכֶ֖ם וְעַֽל־נַפְשְׁכֶ֑ם וּקְשַׁרְתֶּ֨ם אֹתָ֤ם לְאוֹת֙ עַל־יֶדְכֶ֔ם וְהָי֥וּ לְטוֹטָפֹ֖ת בֵּ֥ין עֵינֵיכֶֽם׃
Maka taruhlah perkataan-Ku ini di dalam hatimu dan di dalam jiwamu; ikatkanlah semuanya itu sebagai tanda pada tanganmu, dan semuanya itu harus menjadi tefilin di antara kedua matamu.
Mishnah Sanhedrin
There is greater stringency in respect to the teachings of the scribes than in respect to the torah: [thus,] if [a rebellious elder] says, there is no commandment of tefillin, so that a biblical law may be transgressed, he is exempt. [But if he rules that the tefillin must contain] five compartments, thus adding to the words of the scribes, he is liable.