Another difficulty arises. The Bāb does not always say the same thing. There are passages of the Persian Bayan which imply an interval between his own theophany and the next parallel to that which separated his own theophany from Muḥammad's. He says, for instance, in _Waḥid_ II. Bāb 17, according to Professor Browne, 'If he [whom God shall manifest] shall appear in the number of Ghiyath (1511) and all shall enter in, not one shall remain in the Fire. If He tarry [until the number of] Mustaghath (2001), all shall enter in, not one shall remain in the Fire.' [Footnote: _History of the Bābīs, edited by E. G. Browne; Introd. p. xxvi. _Traveller's Narrative_ (Browne), Introd. p. xvii. ] I quote next from _Waḥid_ III. Bāb 15:-- 'None knoweth [the time of] the Manifestation save God: whenever it takes place, all must believe and must render thanks to God, although it is hoped of His Grace that He will come ere [the number of] Mustaghath, and will raise up the Word of God on his part. And the Proof is only a sign [or verse], and His very Existence proves Him, since all also is known by Him, while He cannot be known by what is below Him. Glorious is God above that which they ascribe to Him.' [Footnote: _History of the Bābīs_, Introd. p. xxx.] Elsewhere (vii. 9), we are told vaguely that the Advent of the Promised One will be sudden, like that of the Point or Bāb (iv. 10); it is an element of the great Oriental myth of the winding-up of the old cycle and the opening of a new. [Footnote: Cheyne, _Mines of Isaiah Re-explored_, Index, 'Myth.'] A Bahai scholar furnishes me with another passage-- 'God knoweth in what age He will manifest him. But from the springing (beginning) of the manifestation to its head (perfection) are nineteen years.' [Footnote: Bayan, _Waḥid_, III., chap. iii.] This implies a preparation period of nineteen years, and if we take this statement with a parallel one, we can, I think, have no doubt that the Bāb expected the assumption, not immediate however, of the reins of government by the Promised One. The parallel statement is as follows, according to the same Bahai scholar. 'God only knoweth his age. But the time of his proclamation after mine is the number Waḥid (=19, cabbalistically), and whenever he cometh during this period, accept him.' [Footnote: Bayan, _Brit. Mus. Text_, p. 151.] Another passage may be quoted by the kindness of Mirza 'Ali Akbar. It shows that the Bāb has doubts whether the Great Manifestation will occur in the lifetime of Baha-'ullah and Ṣubḥ-i-Ezel (one or other of whom is addressed by the Bāb in this letter). The following words are an extract:-- 'And if God hath not manifested His greatness in thy days, then act in accordance with that which hath descended (i.e. been revealed), and never change a word in the verses of God.