Parashas Metzora · Passuk 14:21
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “One lamb” — R’ Akiva asked R’ Nechemiah: Why does the verse say “one”? He replied: This one brings according to his means, and one who defiles the Sanctuary also brings according to his means; one might think that just as the one who defiles the Sanctuary brings two in place of one, so this one brings two in place of one; therefore it says “one.”
Single lamb for the poor metzora
Chazal limit the poor metzora to a single lamb; he does not substitute two birds for the missing animal as is done in other sliding-scale offerings.