Deuteronomy 30:19, Heaven and earth to bear witness against you. We find this phrase used elsewhere in the Scriptures to denote a lack of obedience or awareness to the plans and purposes of YHVH on the part of his people (Deut 4:26; 30:19; 31:28; 32:1; Luke 19:40).
The Scriptures say that in any legal matter a word is to be established only in the mouth of two or three witnesses (Num 35:30; Deut. 17:6; 19:15; Matt 18:16). Heaven and earth are two witnesses against the people of YHVH for their disobedience to his covenants.
What happens to these two witnesses after the Millennium (or Messianic Era) who (anthropomorphically speaking) have seen and heard all the sins of YHVH’s people and when sin (after the white throne judgment of Rev 20:11–15) is once and for all expunged from the earth via the cleansing flames of the lake of fire? They are destroyed (Rev 21:1)! Elohim will mercifully remove the indicting evidence against man’s sinful rebellion. HalleluYah!
Hirsch in his commentary on this verse states that Elohim sends the warning first by means of heaven and earth, and if no notice be taken, uses them as his instruments for the ruin of the guilty ones, even as they are the agents of his blessings when we have made ourselves deserving of them by devotion to our duty (The Pentateuch/Devarim, p. 605).
Recognizing that heaven and earth are agents of both YHVH’s blessings and curses upon his people, it behooves us to take notice of the hurricanes, tornados, earthquakes, floods, droughts and other natural calamities that are striking our nation as we are increasingly heading down the path of moral and spiritual decay and perversion toward outright rebellion and wickedness.