Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 10:3.
Aaron was told that he and his remaining sons should not mourn Aaron's sons who were killed. As priests, they must put priestly work first, before their mourning and personal problems.
#### Other possible translation difficulties in this chapter ####
##### "Unapproved fire" #####
The phrase "unapproved fire " indicates that Aaron's son offered an unacceptable sacrifice. Because of Yahweh's holiness, this was a serious sin. They may have offered a sacrifice at the wrong time or in the wrong way. (See: [[rc://en/tw/dict/bible/kt/holy]] and [[rc://en/tw/dict/bible/kt/sin]])