Job 31:38

If my land cry against me, or that the furrows likewise thereof complain;

Job 31:38 belongs to Job's defense and protestation of his integrity, in which he challenges God to judge him if his moral character is stained. It stands within the poetic argument between Job and his friends about suffering and its cause. In the verse he calls upon his land and its furrows to cry out and complain against him as testifying evidence if he has done wrong.

The chapter as a whole is Job's protestation of his integrity. It gives a much stronger proof of what makes a man honest. That proof goes far beyond merely being free from debt to fellow men and owing no one anything.