And you shall not is the same prohibitive form used in the Ten Commandments. Go up is the general word for ascend. By steps is a word derived from the word for go up. It refers to a way or a means of ascending, such as steps. To my altar may refer to either the “altar of earth” in verse 24 or the “altar of stone” in verse 25. Yahweh considers either one to be his altar. Other ways to render this are “Do not build an altar to worship me that has steps” or “When you build an altar to worship me, don’t make any steps leading up to it.”

That your nakedness be not exposed on it is literally “where you [singular] shall not uncover your genital area upon it.” This suggests two things: that the priests wore loose clothing that exposed their private parts to the ground, and that they were never supposed to stand at such a level that would expose this nakedness to any part of the altar. The background for this law may have been an early prohibition against high altars used for worshiping a “high god.” But this is only one of several theories, so the translator should not force the text to say more than it clearly implies. In languages that must avoid explicit mention of the genitals, one may use a euphemism; for example, “you will expose yourselves” (Good News Translation, and similarly Contemporary English Version), or “your private [or, hidden] parts will be seen.”

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .