*Minor differences ignored. Grouped by changes, with first version listed as example.
to see when the holy things are covered - Render: to see the holy things for an instant. The expression means Iiterally" as a gulp," i. e. for the instant it takes to swallow.
When the holy things are covered - Literally, כבלע keballa, when they are swallowed down; which shows the promptitude with which every thing belonging to the holy of holies was put out of sight, for these mysteries must ever be treated with the deepest reverence; and indeed without this they could not have been to them the representatives of heavenly realities. See the concluding note Numbers 4:36 (note).
But they shall not go in to see when the holy things are covered,.... They were not to be present while they were packing up, test they should see any of them with their eyes; they were not to go in until they were quite covered out of sight; which may signify the hiding of the mysteries of grace in those things under the former dispensation, when even the Levites themselves were not admitted to a sight of them; see Ephesians 3:4,
lest they die; by the immediate hand of God.
כּבלּע, "like a swallow, a gulp," is probably a proverbial expression, according to the analogy of Job 7:19, for "a single instant," of which the Arabic also furnishes examples (see A. Schultens on Job 7:19). The Sept. rendering, ἐξάπινα, conveys the actual sense. A historical illustration of Numbers 4:20 is furnished by 1-Samuel 6:19.
(Note: According to Knobel, Numbers 4:17-20 have been interpolated by the Jehovist into the Elohistic text. But the reasons for this assumption are weak throughout. Neither the peculiar use of the word shebet, to which there is no corresponding parallel in the whole of the Old Testament, nor the construction of נגשׁ with את, which is only met with in 1-Samuel 9:18 and 1-Samuel 30:21, nor the Hiphil הכרית, can be regarded as criteria of a Jehovistic usage. And the assertion, that the Elohist lays the emphasis upon approaching and touching the holy things (Numbers 4:15; Numbers 8:19; Numbers 18:3, Numbers 18:22), and not upon seeing or looking at them, rests upon an antithesis which is arbitrarily forced upon the text, since not only seeing (Numbers 4:20), but touching also (Numbers 4:19), is described as causing death; so that seeing and touching form no antithesis at all.)
*More commentary available at chapter level.