“Then shall the Kohen command to take for the person to be cleansed two living clean birds, and cedar-wood and red wool, and hyssop.” Why does the Metzora specifically take these items? Rashi explains, since he spoke Lashon HaRa and was high and haughty like a cedar tree, he must lower himself like a worm (Tolaas) and a hyssop (Aizov).
Maskil L’David asks, why is it necessary for him to use 2 symbolic items to bring him to humility – the Tolaas Shani and the Aizov – wouldn’t it have driven home the point with one?
Maskil L’David explains, although by other midos – character traits, we say that a person should take the middle of the road, not going to an extreme on either end of the spectrum, however concerning Gaavah – haughtiness – Chazal tell us “Miod Miod Havay Shfal Ruach” – one should be exceedingly humble. It is for that reason that 2 signs of humbleness were used – to stress that the Metzora should be exceedingly humble to atone his sin.