Unto his stature (epi thn hlikian autou). The word hlikian is used either of height (stature) or length of life (age). Either makes good sense here, though probably "stature" suits the context best. Certainly anxiety will not help either kind of growth, but rather hinder by auto-intoxication if nothing more. This is no plea for idleness, for even the birds are diligent and the flowers grow.