Rashi on Exodus 20:21/רש"י על שמות כ׳:כ״א

1מזבח אדמה AN ALTAR OF EARTH [SHALT THOU MAKE] — i. e. an altar attached to the earth, meaning, that they should not build an altar upon columnes or upon a base but it must rest upon the actual ground. Another explanation is, that one should fill the hollow interior of the copper altar (Exodus 27:8) with earth at the time when they encamp, and then erect it for the purpose of sacrifice (Mekhilta).

2תעשה לי THOU SHALT MAKE FOR ME — this implies that from its very beginning it shall be made for My Name (i. e. for the service of Me).

3וזבחת עליו AND THOU SHALT SACRIFICE (slaughter) עליו — i. e. near it, in the same sense as, (Numbers 2:20) “and by him (ועליו) the tribe of Manasseh”. Or perhaps this is not the meaning, but it means “[thou shalt slaughter] upon it”, in its literal sense? This cannot be so, because it states, (Deuteronomy 12:27) “[And thou shalt offer thy burnt offerings] as regards the flesh and the blood upon the altar of the Lord thy God”, but the slaughtering shall not be on the top of the altar (Mekhilta).

4את עלתיך ואת שלמיך THY BURNT OFFERINGS AND THY FEAST OFFERINGS which are from (belong to) thy flocks and thy herds. [את צאנך ואת בקרך are thus a further explanation of the words את עלתיך ואת שלמיך‎].

5בכל המקום אשר אזכיר את שמי IN ALL PLACES WHERE I MENTION MY NAME — This means: where I will give you permission to mention My Proper Name, there אבא אליך וברכתיך I WILL COME TO THEE AND I WILL BLESS THEE — I will make My Shechina rest upon thee. From this you may learn that He did not give any permission to mention (pronounce) His Proper Name except in the place where the Shechina would come — and this is the Chosen House (another term for the Temple at Jerusalem). He gave permission to the priests to pronounce His Proper Name there whilst lifting up their hands to bless the people (cf. Mekhilta; Sotah 38a; and Rashi on Numbers 6:27).