These are the names of the sons of Aaron introduces the list of Aaron’s sons. The naming formula These are the names occurs periodically throughout the Pentateuch (see, for example, 1.5; 34.17; Gen 25.13; Exo 6.16). As a formula it should be rendered consistently on each occasion, even if not literally.

Nadab the first-born, and Abihu, Eleazar, and Ithamar: See Exo 6.23. Aaron’s sons are listed in their birth order. In Hebrew the conjunction and occurs twice in this list (also in Exo 6.23; 28.1; Num 26.60; 1 Chr 24.1). It may occur the first time to set off Nadab from his younger brothers. In many languages it will be better to use this conjunction only once, just before the last name (so Good News Translation).

Quoted with permission from de Regt, Lénart J. and Wendland, Ernst R. A Handbook on Numbers. (UBS Helps for Translators). Miami: UBS, 2016. For this and other handbooks for translators see here .