Zechariah 12:2

Behold, I will make Jerusalem a cup of trembling unto all the people round about, when they shall be in the siege both against Judah and against Jerusalem.

Behold, I will make Jerusalem a cup of trembling - a cup, causing those who drink it to reel; from a Hebrew root to reel [ raa`al (H7477)]. Jerusalem, who drank the "cup of trembling" herself, shall be so to her foes (Isaiah 51:17; Isaiah 51:22; Jeremiah 13:13). Calvin, with the Septuagint, translates [ cap (H5592)], 'a threshold of destruction,' on which they shall stumble and be crushed when they attempt to cross it. The English version is better. However, the term is often used of a basin or large vessel placed at the upper threshold. And the Septuagint translate it, 'the vestibule' [prothura]. So that the cup of trembling is to be drunk by the enemy when he has reached as far as the very threshold of the city.

When they shall be in the siege both against Judah and Jerusalem. The Hebrew order of words is literally 'And also against Judah shall he (the foe) be in the siege against Jerusalem:' implying virtually that Judah, as it shares the invasion along with Jerusalem, so it shall, like the metropolis, prove a cup of trembling to the invaders. Maurer, with Jerome, translates, 'also upon Judah shall be the (cup of trembling); i:e., some Jews forced by the foe shall join in the assault on Jerusalem, and shall share the overthrow with the besiegers. But Zechariah 12:6, show that Judah escapes and proves the scourge of the foe.