According to Muhammad Musṭafá (p. 108), Táhirih arrived in Karbilá in the year 1263 A.H.[1846-47] She visited Kúfih and the surrounding district, and was engaged in spreading the teachings of the Báb. She shared with the people whom she met the writings of her Master, among which was His commentary on the Súrih of Kawthar.
(Footnotes to chapter 15 of “The Dawn-Breakers’, provided by Shoghi Effendi)