Subh-i-Azal was designated by the Báb as his successor when he was 16 or 17 years old.

A Turkish dervish who, impelled by curiosity to see so celebrated a heresiarch, visited him soon after his arrival in Cyprus, remarked with surprise "He is still but a child!" Gobineau (p. 277) makes his age only 16 at the time of the Báb's death (A.D. 1850), but it is more probable that this was his age when he was designated by the Báb as his successor, in which case he would be about 19 when he actually succeeded. Bearing in mind the extraordinary virtue attributed by the Bábís to this mystical number, we may well believe that such a coincidence would strongly influence the choice of the faithful in his favour.

(A Traveller's Narrative, p. 374)

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