A shift in political power often brings new dangers for a recovering nation. The regime change in the Persian Empire provided the perfect opportunity for the enemies of Judah to try and stop the restoration of Jerusalem. The primary approach among commentators is that the new ruler, who took power after Cyrus, is the very same King Ahasuerus known from the story of Esther [רש"י, רלב"ג]. However, another perspective identifies him as the Persian king Artaxerxes [אבן עזרא].
As soon as the new king's reign began, the enemies of the Jewish people drafted a formal letter of accusation and slander [מצודת ציון, ביאור שטיינזלץ]. Acting as a deliberate adversary [אבן עזרא, רב סעדיה גאון], they aimed to weaken the resolve of the people living in Judah and strike fear into their hearts. Their primary goal was to ensure the new king would not grant permission to continue the construction of the Temple [רש"י, מצודת דוד, מלבי"ם].
Deep historical motives and familiar figures drove this malicious effort from behind the scenes. The document was penned by Shimshai the scribe, the son of the wicked Haman. Furthermore, the plot received full backing from Queen Vashti. As the granddaughter of Nebuchadnezzar, the man who originally destroyed Jerusalem, she fiercely opposed any attempt to rebuild the sacred site her ancestors had ruined.
Ultimately, the success of this slanderous letter and the subsequent halt in construction were not merely the results of political scheming, but a direct reflection of God's providence. The seventy years of exile decreed upon the nation had not yet come to an end. The builders of the Temple had miscalculated the timeline, counting the years from the actual destruction of the building rather than from earlier events. Because the proper time for complete redemption had not yet arrived, God allowed these wicked individuals to successfully incite the government, causing the building efforts to be suspended for many long years [רב סעדיה גאון].