John the Baptist was Elias
Below is one of the references to Elias mentioned by ''Abdu'l-Baha from the Gospel of Matthew: (8:21)

And his disciples asked him, saying, Why then say the scribes that Elias must first come? And Jesus answered and said unto them, Elias truly shall first come, and restore all things. But I say unto you, That Elias is come already, and they knew him not, but have done unto him whatsoever they listed. Likewise shall also the Son of man suffer of them. Then the disciples understood that he spake unto them of John the Baptist. [mat 17:10-13] (8:22) see

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