Another interpretation: until now I still have to raise up the King Messiah, of whom it is written, "For unto us a child is born" (Isaiah 9:5).
Still Ahead Lies the Raising of the King Messiah
Yalkut Shimoni on Torah 133:21
דָּבָר אַחֵר, עַד עַכְשָׁו יֵשׁ לִי לְהַעֲמִיד מֶלֶךְ הַמָּשִׁיחַ, שֶׁכָּתוּב בּוֹ "כִּי יֶלֶד יֻלַּד לָנוּ".