פּירוש אויף שמות 30:20

בבאם אל אהל מועד WHEN THEY COME INTO THE APPOINTED TENT to burn incense in the morning and at evening, or to sprinkle of the blood of the bullock offered by the anointed High-Priest (Leviticus 4:5, 7) and of the he-goats offered as atonement for the sin of idolatry (all of which services were performed in the interior of the Sanctuary) (Zevachim 19b).

ירחצו מים, “they shall wash with water;” this has been repeated as they had to wash themselves both before going in or even when approaching the golden altar to offer incense.

The incense, morning and afternoon. . . Rashi [mentions burning the incense because he] holds that there is no death penalty for merely entering [the Tent of Meeting without washing,] if they do not perform service. And so it says in Zevachim 19b, that the words “for Divine service” in our verse refer [also] to “Entering the Tent of Meeting.” (Nachalas Yaakov)

ולא ימתו THAT THEY DIE NOT — thus it follows that if they do not wash they will die: You may rightly draw this conclusion for in the Torah laws are sometimes stated only by implication: consequently from what is said here in the negative (that they die not) you may derive the positive (that they will die if they do not observe the law here laid down).

אל המזבח [OR WHEN THEY STEP] NEAR THE ALTAR — i. e. the outer altar, in which case there is no entering into the appointed tent but the service is performed in the court.