Bedouins, meaning those around Medina. "And among the people of Medina are those who are persistent in hypocrisy," meaning: they have become emboldened in it. "You do not know them, [but] We know them." Allah and His Messenger made them known thereafter, and the Prophet (peace and blessings of Allah be upon him) disclosed them to Hudhayfah ibn al-Yaman.
"We will punish them twice." As for one of them, it is by means of the Zakah being taken from them by force, and as for the other, it is the punishment of the grave. "Then they will be returned to a great punishment," meaning: Hellfire.
Surah At-Tawbah from verse (102) to verse (106).