The Hebrew for humility is hach'na'ah, spelled hay, chof, nun, ayin, hay... the numerical equivalent of 5, 20, 50, 70, 5. These numbers add up to 150. There are 150 chapters of psalms. Nebuchadnezzar called on every nation to bow down to him, in his tremendous egoism. It is a famous story that the Jews he chose to bow down refused the request and were thrown into a fire, and emerged unscathed. Upon seeing this, Nebuchadnezzar began composing verses of praise to G-d. Our sages say that these songs would have been greater than the songs of King David. Then an angel came and hit Nebuchadnezzar. When he was hit, Nebuchadnezzar stopped composing songs and cursed G-d.

This lack of humility, (humility is the numerical equivalent of 150), is the reason why Nebuchadnezzar was unable to compose the psalms, which have 150 chapters.

- adapted from R. Kirzner's tape, The Deepest Music of the Jewish Soul