The tefillin are not worn on Sabbath or Festival. The observance of these days is “a sign for ever” of our belief “that in six days the Lord made the heavens and the earth.” The very days of rest thus remind us of the truths of which the tefillin are “a sign.” The tefillin became, therefore, unnecessary on those days. The commandment of tefillin applies to all male persons from their thirteenth birthday. [52] The performance of this commandment is preceded by the usual benediction (‏ברכת המצות‎), concluding ‏להניח תפלין‎, “to place the tefillin,” scil., on the arm and on the head. According to the German rite, a second benediction is recited before placing the tefillah shel rosh on the head, viz., ‏על מצות תפלין‎, “concerning the commandment of tefillin.” [53] In order to prevent a mere perfunctory observance of this commandment, we are taught to reflect on the importance and the object of the tefillin, and to declare that by placing the tefillin on the head and on the arm, near the heart, we indicate our consciousness of the duty to employ the thoughts that rise in our mind, and the desires of our heart, in the service of the Lord, who gave us the powers of thought and will. [54] ‏מזוּזה‎ Door-post Symbol. The Mezuzah is a piece of parchment on which the two first paragraphs of Shema (Deut. vi. 4–9, xi. 13–20) are written. The parchment is rolled together, put into a small case, and fixed on the right-hand door-post. A small opening is left in the case, where the word ‏שַׁדַּי‎ “Almighty,” written on the back of the scroll, is visible. [55] The object of the mezuzah, commanded in the words, “And thou shalt write them on the door-posts of thy house and upon thy gates” (Deut. vi. 9 and xi. 20), is to remind us of the Presence of God, of His Unity, Providence, and Omnipotence, both on entering our home and on leaving it; of the all-seeing eye that watches us, and of the Almighty who will one day call us to account for our deeds, words and thoughts. The mezuzah thus serves to sanctify our dwelling and protect it from being polluted by evil deeds. Signs of God’s Covenant. Besides the signs mentioned above, there are two other signs of the covenant between God and Israel. 1. Sabbath is called “an everlasting covenant,” and “a sign between God and the children of Israel for ever” (Exod. xxxi. 16, 17). See pp. 254 sqq. and 339 sqq.