Baha'u'llah laments being surrounded by the Jews of Israel

"This Holy Land hath been mentioned and extolled in all the sacred Scriptures. In it have appeared the Prophets of God and His chosen Ones. This is the wilderness in which all the Messengers of God have wandered, from which their cry, "Here am I, here am I, O my God" was raised. This is the promised Land in which He Who is the Revelation of God was destined to be made manifest. This is the Vale of God's unsearchable decree, the snow-white Spot, the Land of unfading splendor. Whatever hath come to pass in this Day hath been foretold in the Scriptures of old. These same Scriptures, however, unanimously condemn the people that inhabit this land. They have, at one time, been stigmatized as the "generation of vipers." Behold how this wronged One is now, whilst surrounded by a "generation of vipers," calling aloud and summoning all men to Him Who is the world's Ultimate Desire, the Summit and Day Spring of Glory. Happy is the man that hath hearkened to the voice of Him Who is the Lord of the Kingdom of Utterance, and woe betide the heedless, they that have strayed far from His truth."

https://bahai-library.com/writings/bahaullah/gwb/164.html

"generation of vipers" is a reference to Bible verses such as this:

“But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come?”

-Matthew 3:7

Clearly the generation of vipers is the Jews.