Say: Shame on you, pig, and what your hands have done, as you tested the sword of your self on the face of God and became arrogant towards God, the bestower of faith, the powerful, the holy. (Surat an-Nus'h)
So Baha'u'llah swore himself. It doesn't surprise me, and I don't necessarily think that swearing is bad. But it is just one more example of how the current, Westernized, Bahai faith, is completely different from its historical roots.
Some of the letters of Bahaullah are really vile, and I would get angry if a person talked to me like that. This seems to be the modus operandi of Bahaullah. He sends a letter to a king or influential person, complaining and attacking them, and then complain more when they won't respond. And so the victimization cycle continues.
Another translation here :
From Suratu’l Nus’h: Provisional Translation
Say: Woe to you, O swine! For what your hands have wrought to the extent that you have drawn the sword from its sheath towards the Countenance of God, and waxed arrogantly against God, the Help in Peril, the Mighty and Most Holy.
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