The Previous Lubavitcher Rebbe, Rabbi Yosef Yizchak Schneersohn, once declared:[1]
“Moshiach is already here: ‘Behold, he is standing behind our wall.[2]’
“In more supernal worlds, there is already joy and merriment that he has come! However, in this world, he is waiting that the Jewish People repent.”
When our holy Rebbes beheld that Moshiach was ready to come, they saw that he has indeed already come in heaven. All that is left to do is that last action that will tip the scale. So what are we waiting for?!
[1] Sefer HaSichos 5701, Pg. 81.
[2] Shir HaShirim 2:9.