Matthew Poole and continuators on Leviticus 21:2

2 But for his kin that is near unto him , that is, for his mother, and for his father, and for his son, and for his daughter, and for his brother ,

Under which general expression his wife seems to be comprehended, though she be not expressed in the following instances, because from the mention of others more remote it was easie to gather that so near a relation was not excluded. And hence it is noted as a peculiar and extraordinary case, that Ezekiel, who was a Priest, was forbidden to mourn for his wife, Ezek. 24. 16. &c. These exceptions God here makes in condescension to humane infirmity, because in such cases it was very hard to restrain the affections. But this allowance concerns onely the inferiour Priest, not the High-priest, as we shall see.

Obj. Eleazar and Ithamar are forbidden to mourn for their brethren, Nadab and Abihu. Ans. 1. That case was singular, both because such a mourning might seem to be a censure of Gods severity upon them, and because they were then in the actual execution of their office and in their initiation to it, and they were the onely persons, besides Aaron, that could perform that work, and therefore their attendance upon it was more necessary then it would be in after times and other cases. 2. The latter law can either limit or enlarge the former at the pleasure of the lawgiver. And this law may seem to be added least that prohibition Lev. 10. should be taken for a general rule.