The tenth section of the Amidah daily prayer is for the gathering of the Jewish exiles to Israel:

Sound the great shofar for our freedom,
raise the ensign to gather our exiles,
and gather us from the four corners of the earth.
Blessed are you, O Lord, who gathers the dispersed of his people Israel.

God gave the nation of Israel the Promised Land, but they were exiled when they turned their back on the Lord and disobeyed His precepts and laws.  God promises to bring them back together again, but does not say when.  So they pray expectantly for God to fulfill His promises in His time.

When Jesus cam on the earth, He desired the same thing – that Israel would be reunited to God.  But instead, the Jews hated him and rejected Him as Messiah.  listen to Jesus’ words to the Israelites:

 “Jerusalem, Jerusalem, you who kill the prophets and stone those sent to you, how often I have longed to gather your children together, as a hen gathers her chicks under her wings, and you were not willing.”  (Matthew 23:37)

The Apostle Paul, in writing to the church in Rome, reminds the Jewish believers that God still has His offer of reconciliation and restoration toward the Israelites.  He even tried to use jealousy to bring His own back to Himself (Romans 10:19-20).  But still, even with God’s offer still extended lovingly toward His own, they rejected Him:

But concerning Israel he [God] says,