Isaiah 2:3

Many people shall go and say,
 
“Come, and let us go up to the mountain of the Lord,
    to the house of the God of Jacob,
and He will teach us of His ways,
    and we will walk in His paths.”
For out of Zion shall go forth the law,
    and the word of the Lord from Jerusalem.
Isaiah 2:3, Modern English Version (MEV)
 
One of the things we often fail to fully appreciate is the place the Temple held in the Jewish psyche, and still does even today. The Temple was where God was. First it was the Tabernacle in the wilderness. Then it was the Temple built by Solomon. And while the glory, or Shekinah of God was never reported as inhabiting the Second Temple, the prophets were fairly consistent that He would in a future Temple. Therefore, one would be required to go to Jerusalem to have any dealings with God. That's where He would reside, and nowhere else.