"AND THE PEOPLE WEPT ON THAT NIGHT..." (Bamidbar 14:1))
The fundamental principle of the Universe is the Kindliness of the Creator, and Man's first duty is to recongnise this kindliness and to proclaim it... When men weep without cause, they thereby propagandise against Hashem's kindliness. We commermorate this principle when we mourn on the Ninth of Av by looking back to recognise the happiness which we formerly possessed but which we failed to appreciate fully. -- Journey into Greatness.