PRONOUNS, RELATIVE AND INTERROGATIVE. Relative with supplementary pronoun; origin ofRelative with Supplementary Pronoun. With the Germans it is still customary, when the antecedent is a pronoun of the first or second person, to repeat the pronoun for the sake of defining the person, because the relative is regarded as being in the third person. Thus "Thou who thou hearest," &c. The same repetition was common in Anglo-Saxon (and in Hebrew) for all persons. "That (rel.) through him" = "through whom," "a tribe that they can produce" = "a tribe who can produce," &c. Hence in Chaucer, Prol. 43-45:
A knight ther was, and that a worthy man, That, from the tymë that he first began To ryden out, he lovede chyvalrye;and in the same author "that his" = "whose," "that him" = "whom," &c. In the same way in Elizabethan authors, when the interrogative who (251) had partially supplanted that as a relative, we find who his for whose, whom him for whom, which it for which, &c. The following is probably not a case of the supplementary pronoun:
That . . . his is not elsewhere used in Shakespeare, that I know of. The above probably means "than this (fellow, who is) a mere devil-in-the-play, so that every one may beat him."
“Bardolph and Nym had ten times more valour than this roaring
devil i' the old play, that every one may pare his nails with a wooden