Brake up for it my decreed place, i.e. made those valleys, or channels, and hollow places in the earth, which might serve for a cradle to receive and hold this great and goodly infant when it came out of the womb. See Genesis 1:9,10 Psa 33:7. Or, ordained or established my decree upon or concerning it. Set bars and doors, i.e. fixed its bounds as strongly as if they were fortified with bars and doors.
Related Commentaries of Job 38:10
Job 38:10
10 And brake up for it my decreed place, and set bars and doors,