וְחֶזְוֵ֥י רֵאשִׁ֖י עַֽל־מִשְׁכְּבִ֑י חָזֵ֣ה הֲוֵ֔ית וַאֲל֥וּ אִילָ֛ן בְּג֥וֹא אַרְעָ֖א וְרוּמֵ֥הּ שַׂגִּֽיא׃
Thus were the visions of my head upon my bed: I saw, And behold a tree in the midst of the earth, And the height thereof was great.
Read kabbalistic (mystical) interpretation of Daniel 4:7: and classical mystical sources.