Variantly: An analogy: A king and his son are traveling by coach until they come to a narrow place, where his coach overturns on his son, whose eye is blinded, his foot severed, and his hand broken. When he comes to this place (in the future), he mentions two or three times: "Here my sons' eye was blinded, his foot was severed, and his hand broken." Here, too, the Holy One Blessed be He mentioned mei merivah (the waters of contention) three times (Bamidbar 20:13, Ibid. 24, Devarim 33:8), saying (as it were) "Here I killed Aaron, here I killed Moses." And thus is it written (Psalms 141:6) "Their judges (Moses and Aaron) have 'slipped' by (hitting) a rock." (viz. 11:20).