Halakhah zu Jirmejahu 1:18

Song of Songs 8:9 declares "If she be a wall we shall build upon her a turret of silver; but if she be a door we shall enclose her with panels of cedar." According to Rashi, God addresses Israel and describes two alternative modes of conduct open to Israel in the Diaspora. The community of Israel may resolve to "be a wall," and to comport itself as if fortified with "walls of brass" (Jeremiah 1:18) which cannot be penetrated, i.e., Israel may gird herself as a defensive wall, withstand incursions and refuse to allow the nations to infiltrate through intermarriage. If Israel acts in this manner "a turret of silver" will be erected, i.e., Israel will survive to witness the rebuilding of the Holy City and the Temple. However, if the community of Israel "be a door which revolves on its hinges," the result will be far different. If Israel wavers and succumbs to every alien knock, opening her door to foreign nations through intermarriage, rather than being fortified with noncorroding silver, her doors will be lined with wooden panels which are exposed to rot and decay. The corrosive effect of intermarriage is such that the community decays and withers away.