When I was last with you I asked the question:
Just who are the 99?
We started to answer it by pointing out that when the Saviour came to earth some 2000 years ago, He left behind His father, His glory and the glorious company of Heaven in order to save His people.
I believe 'that leaving' is what is referred to here!
The flock spoken of here could not be an 'earthly' body of people for a number of reasons.
Because of their description. " . . . . ninety and nine just persons, which need no repentance," verse 7. This cannot refer to any group of human beings, not even the saved!
". . . . there is no man that sinneth not," 1 Kings 8:46
" . . . for all have sinned, and come short of the glory of God," Romans 3:23.
Saved and converted sinners are ever in need of repentance. Rev 2:5, 16; 3:3, 19. "If we say that we have no sin, we deceive ourselves, and the truth is not in us," 1 John 1:8.
"All of a Christian's life is one of repentance." Martin Luther.