Genesis - Chapter 45

The first time the family of Israel met with Joseph they did not recognise him, or know who he was.  But the second time (in this chapter) he revealed himself to them.  And at this second coming to him, they receive his mercy and forgiveness and love.

And that is how it was with the nation of Israel.  When Jesus came to them the first time they did not recognise him and they crucified him.  On his second coming he will reveal himself to the nation Israel and they will receive his mercy and forgiveness and love.  And in Revelation chapter 7 we see 144,000 being sealed by God - 12,000 from each of the tribes of Israel.