“On that day I swore to them that I would bring them out of Egypt into a land I had searched out for them, a land flowing with milk and honey, the most beautiful of all lands.” Ezekiel 20:6
If a land is flowing with honey it means the bees are present and thriving, which means the vegetation is also flourishing since bees pollinate the plants. And if the land is flowing with milk it means the animals are thriving and giving birth. So a land flowing with milk and honey signifies abundant and thriving plant and animal life, a land full of vitality and devoid of famine or scarcity. As long as humans take proper care of the earth by following the blueprint God laid out in Eden for them, including not eating animals and taking care of the land, the whole earth will be flowing with milk and honey just as God has promised since the beginning. All that is required is to put our faith in God and to follow his ways.
This phrase was commonly understood among Hebrew-speaking people at the time the scripture was being recorded. It meant the land was flourishing the way God had intended it to from the beginning (Genesis 1:31). It did not mean we are exploiting bees and cows to serve the desires of the flesh but instead that we are being the proper stewards of the earth that God instructed us to be, tilling the ground (Genesis 2:15) and caring for the animals (Genesis 1:28, 2:19), and that all the land is flourishing as a result (Genesis 1:31). It means we are maintaining the good kingdom God created the earth to be (Matthew 24:45) and we and this earthly home God gave us (Isaiah 45:18) are blessed as a result (Genesis 1:28, Proverbs 16:20, Deuteronomy 28, Luke 11:28).