Theodor Heuss, 'Hitler's Weg'. Hitler's previously quoted remark comes from his speech of 6th November 1937, to the original party members. Similarly, in his speech on 8th November 1933, commemorating the same occasion, he had declared:
'This evening and this day made it possible for us afterwards to fight a battle for ten years by legal means: for, make no mistake, if we had not acted then I should never have been able to found a revolutionary movement, to form it and keep it in being, and yet all the time maintain legality.' (Norman H. Baynes, ed., The Speeches of Adolf Hitler, April 1922-August 1939).