Deuteronomy 32:1Meaning & Commentary from the Church Fathers

Furthermore, just as Moses sought to lead the Israelites into the Promised Land and foresaw that they would overlook its blessings, he proclaimed, "Listen, O heaven, and let the earth bear witness to the words of my mouth." I provide testimony to you, O Israelites, by heaven and earth, says Moses, that if you enter the Promised Land and forsake the Lord your God, you will be scattered among all nations. Similarly, Isaiah, when the impending threat was about to manifest, could not summon Moses, who had already passed, nor those who had obeyed him long ago as witnesses. Instead, he calls upon the very elements through which Moses testified. Look, you have strayed from the promise; you have abandoned God: how can I summon you, Moses, as my witness? You are deceased. How can I call upon Aaron? He surrendered himself to death. Are you unable to testify for me? Call upon the elements: for during my lifetime, I bore witness not through Aaron or anyone else who has passed on, but through the enduring elements—heaven and earth. Thus, Isaiah proclaims, "Listen, O heaven, and give heed, O earth," you who are called upon today as witnesses. He does not call these elements merely for that reason, but also because he spoke to the Israelites. "Hear, O heavens," for you rained down manna; "inspire, O earth," for you provided quails. "Hear, O heaven," listen, for you showered down manna, revealing the miraculous—likened to a threshing floor. "You shall inspire the earth," for you descended to create the meal without preparation. Nature was idle, yet grace was at work. The oxen did not toil, yet the grain sprang forth; there was no hand of the cook, no organization, yet manna, the sanctified spring had served as all that they needed. Nature forgot its frailty. How did their garments not wear out? How did their shoes remain intact? All was abundantly provided for their needs. "Listen, O heaven, and compel, O earth." Despite all the declarations of divine favor and evident blessings, the Lord endures disdain. To whom shall I reveal my message, if not to you? I find no one to hear me. Look, I have come, and there was no one; I spoke, and there was no listener. I address the unreasonable, for those who are reasonable have fallen short of the unreasonable.

In this regard, Jacob and Laban referred to the mound as a heap of testimony (Genesis 31:47), while Abraham and Abimelech, the king of Gerar, named the location a well of oaths, since there they entered into a covenant with an oath (Genesis 21:31). Refer also to Psalm 49:4.