John Wesley on 1 Chronicles 24:6

One, &c. - Or, the chief of one house of the fathers was taken (by lot) for Eleazar (out of his family) and that which was taken after it was taken for Ithamar, out of his family. So the first lot fell to Eleazar, and the second to Ithamar, the third to Eleazar, and the fourth to Ithamar, so successively, 'till all the families of Ithamar had received their lots. And afterwards all the lots came forth to the rest of Eleazar's families, which were double in number to those of Ithamar.