September 30

He is the Guardian of the Cause in the very fullness of that term, and the appointed interpreter of its teachings, and is guided in his decisions to do that which protects it and fosters its growth and highest interests.

He always has the right to step in and countermand the decisions of a national assembly; if he did not possess this right he would be absolutely impotent to protect the Faith, just as the N.S.A., if it were divested of the right to countermand the decisions of a local assembly, would be incapable of watching over and guiding the national welfare of the Bahá’í Community.

It very seldom happens—but it nevertheless does happen—that he feels impelled to change a major (as you put it) decision of an N.S.A.; but he always unhesitatingly does so when necessary, and the N.S.A. in question should gladly and unhesitatingly accept this as a measure designed for the good of the Faith which its elected representatives are so devotedly seeking to serve. 
- Shoghi Effendi  (From a letter dated 13 May 1945 written on behalf of Shoghi Effendi; ‘Letters to Australia and New Zealand’)