דַּבֵּ֞ר אֶל־בְּנֵ֤י יִשְׂרָאֵל֙ וְאָמַרְתָּ֣ אֲלֵהֶ֔ם וְעָשׂ֨וּ לָהֶ֥ם צִיצִ֛ת עַל־כַּנְפֵ֥י בִגְדֵיהֶ֖ם לְדֹרֹתָ֑ם וְנָֽתְנ֛וּ עַל־צִיצִ֥ת הַכָּנָ֖ף פְּתִ֥יל תְּכֵֽלֶת׃
"Parle aux enfants d’Israël, et dis-leur de se faire des franges aux coins de leurs vêtements, dans toutes leurs générations, et d’ajouter à la frange de chaque coin un cordon d’azur.
Mishnah Menachot
Regarding the seven branches of the menorah, the [absence of] one invalidates the others. Regarding the seven lamps on it, the [absence of] one invalidates the others. Regarding the two portions of Scripture in the mezuzah, the [absence of] one invalidates the other; indeed even one letter can invalidate the whole. Regarding the four portions of Scripture in the tefillin, the [absence of] one invalidates the others; indeed even one letter can invalidate the whole. Regarding the four fringes, the [absence of] one invalidates the others, since the four together form one mitzvah. Rabbi Ishmael says: the four are four separate mitzvot.