Jamieson, Fausset and Brown on Micah 1:2

2. all that therein is--Hebrew, "whatever fills it." Micaiah, son of Imlah, our prophet's namesake, begins his prophecy similarly, "Hearken, O people, every one of you." Micah designedly uses the same preface, implying that his ministrations are a continuation of his predecessor's of the same name. Both probably had before their mind Moses' similar attestation of heaven and earth in a like case (De 31:28; 32:1; compare Is 1:2).

God be witness against you--namely, that none of you can say, when the time of your punishment shall come, that you were not forewarned. The punishment denounced is stated in Mi 1:3, &c.

from his holy temple--that is, heaven (1Ki 8:30; Psa 11:4; Jon 2:7; compare Ro 1:18).