Mic 3:12 “Therefore will Zion for your sake be ploughed as a field, and Jerusalem become stone heaps, and the mountain of the house become forest heights.” Lâkhēn (therefore) applies primarily to Mic 3:11, directing the threat of punishment by בּגללכם to all the sinners mentioned there; but it also points back to Mic 3:9, Mic 3:10, expressing what is there indicated by “this.” Zion is not “the site on which the city stood,” or Jerusalem, “the mass of houses in the city,” as Maurer and Caspari suppose; but Zion is that portion of the city which contained the royal palace, and Jerusalem the rest of the city (cf. Mic 4:8). The mountain of the house, i.e., the temple hill, is also specially mentioned, for the purpose of destroying all false trust in the temple (cf. Jer 7:4). The predicates are divided rhetorically, and the thought is this: the royal palace, the city, and the temple shall be so utterly destroyed, that of all the houses and palaces only heaps of rubbish will remain, and the ground upon which the city stood will be partly used as a ploughed field, and partly overgrown with bushes (cf. Isa 32:13-14). On sâdeh as an accusative of effect (as a field = becoming a field), see Ewald, §281, e; and for the plural form עיּין, see Ewald, §177, a. Habbayith (the house) is probably chosen intentionally instead of bēth Yehōvâh (the house of Jehovah), because the temple ceased to be the dwelling-place of Jehovah as soon as it was destroyed. Hence in Ezekiel (Eze 10:18., Eze 11:22.) the Schechinah departs before the Babylonians destroy it. With regard to the fulfilment of this threat, see the points discussed at Mic 4:10. Glorification of the House of the Lord, and Restoration of the Dominion of Zion - Mic 4:1-13
Zion will eventually be exalted from the deepest degradation to the highest glory. This fundamental thought of the announcement of salvation contained in Mic 4:1-13 and Mic 5:1-15 is carried out thus far in Mic 4:1-13 : the first section (Mic 4:1-7) depicts the glorification of the temple mountain by the streaming of the heathen nations to it to hear the law of the Lord, and the blessing which Israel and the nations will derive therefrom; and the second section (Mic 4:8-13) describes the restoration of the dominion of Zion from its fallen condition through the redemption of the nation out of Babel, and its victorious conflict with the nations of the world.