Here who=man.
(1) As white—(2) as snow.
Here snow=white.
[§ 526]. It is necessary that the relative be in the same gender as the antecedent—the man who—the woman who—the thing which.
[§ 527]. It is necessary that the relative be in the same number with the antecedent. As, however, who, which, whom, are equally singular and plural, and as what, which is really singular, is not used as a relative, the application of this law is limited to the word whose. Now whose is, etymologically, a genitive case, and a genitive case of the singular number. Hence the expression the men whose daggers stabbed Cæsar can only be justified by considering that the word whose is plural as well as singular. Such is the case. If not the expression is as illogical as homines cujus sicæ, &c. would be in Latin.
[§ 528]. It is not necessary for the relative to be in the same case with its antecedent.
1. John, who trusts me, comes here.
2. John, whom I trust, comes here.
3. John, whose confidence I possess, comes here.
4. I trust John who trusts me.