Midrash su Zaccaria 9:2

(Exodus 19:21) "And the L rd said to Moses: Go down and warn the people": lest they break their bounds to see. "and there fall of them many": If one of them falls, it is (to Me) as if all have fallen; the one detracts from the many. One of them who falls is reckoned against the entire act of creation, viz. (Zechariah 9:2) "for to the L rd (will be) the eye of (one) man and (it will be reckoned as) all the tribes of Israel."