妙法蓮華經玄贊 8.455

8.455

欲顯分身佛數多故。又顯次第至三極者，顯此一乘三乘極故，又顯本穢凡夫位也。初變大千表至聲聞，次變二百萬億那由他國表至獨覺，後更變二百表出二乘至一乘位極滿足故。

Because he wishes to reveal the great number of emanation buddhas. Furthermore, to reveal that proceeding step by step to the three extremes shows that this Single Vehicle is the culmination of the three vehicles; it also reveals the original defiled state of ordinary beings. The first transformation of the trichiliocosm represents reaching the śrāvakas; the next transformation of two hundred myriad kotis of nayutas of lands represents reaching the pratyekabuddhas; the final transformation of yet another two hundred represents transcending the two vehicles to reach the stage of the Single Vehicle, which is fully complete.