The remains of the Bab were kept in the room of Bahiyyih Khanum for ten years

Abdul Baha entrusted her with the sacred remains of the Báb which were housed in her room for some ten years in the house of 'Abdu'lláh Páshá.

https://bahai-library.com/50th-anniversary_greatest_holy_leaf

The construction of the Shrine had begun over forty years ago. The Guardian recounted how the Bab’s Sacred remains journeyed in hiding for decades in Iran before arriving in the Holy Land where they were hidden in the room of the Greatest Holy Leaf for another ten years. ‘Abdu’l-Baha showed the remains to the assembled Baha’is to verify that they had arrived intact, and he buried them with great solemnity in a marble sarcophagus sent by the Baha’is of Burma.

(The Memoirs of Shamsi Sedaghat by Shamsi Sedaghat edited by Hillary Chapman - 2023)

https://bahai-library.com/sedaghat_chapman_memoirs