Musar zu Schemot 34:23

When the Torah (16,16) commands that these pilgrimages have to be made on three occasions annually, this is an allusion to Isaac, an unblemished total offering. In connection with the עקדת יצחק the Torah mentions the word Yireh or Yera'eh three times (Genesis 22, 8-14-14). "Three times a year every male of yours shall be seen by the Lord your G–d in the place G–d will select," corresponds to Genesis 22,8: "G–d will select for Himself the lamb as the total offering my son." This is because the words in Exodus 34,23 "את פני האדון ה' אלוקי ישראל" are an expression of a decree by G–d the "Master" Who decreees that He wants to see them together in one spot. "Three times as year every one of your males shall be seen by the Lord your G–d" (Exodus 23,17), corresponds to the second time the word is used in connection with the עקדה. The third directive to make the pilgrimage to Jerusalem is in our verse here and corresponds to the third time the Torah used the expression יראה in connection with the binding of Isaac. It is a reference to the Mountain of G–d, Moriah. The warning השמר לך (12,13) in this portion not to offer sacrifices anywhere else, corresponds to similar words used by Abraham in his instructions to Eliezer (Genesis 24,6) not to bring Isaac back to Ur Kasdim whence Abraham had emigrated to the land of Canaan. The common denominator to all this is that Isaac, as an unblemished total offering, was not allowed to leave ארץ ישראל.