Genesis 19:34
And it came to pass on the morrow, that the firstborn said unto the younger, Behold, I lay yesternight with my father: let us make him drink wine this night also; and go thou in, and lie with him, that we may preserve seed of our father.
On the morrow after the first night the elder daughter proposed repeating the act that night also, making their father drink wine again and having the younger go in and lie with him in order to preserve their father's seed and gain descendants. The plan and the act were sinful conduct and part of Lot's sins and failures. Even a man favored by God and counted among believers can be overcome by temptation and fall into wrongdoing. Their conduct resulted from wicked associations during their sojourn in Sodom. Association with corrupt people had perverted their morals and confused their sense of right and wrong in their minds, until they lost the ability to distinguish good from evil and sin no longer appeared sinful to them.
Their children became like the wicked people of Sodom. They are identified as the Moabites and Ammonites, idolatrous peoples opposed to God and His people. That even his two rescued daughters were morally corrupted shows Lot had remained so long among the wicked that he was able to save only himself and them. The verse belongs to the Sodom account whose practices were depraved and dangerous to purity. Its destruction shows the corruption found in Canaan also brought judgment on Sodom, and contact with evil spirits and the resulting corrupt practices lead people away from God toward ruin.
Sodom and Gomorrah illustrate what cities become as the world grows worse and worse. Modern cities including Melbourne are becoming like Sodom and Gomorrah, and this likeness is a sign of the times to be discerned. Building large plants and establishing business interests in such cities goes without God's counsel and blinds people so they do not discern it. The account is preserved to expose the faults of even believers so later readers can learn from them as a warning and lesson and avoid the same evils. It calls readers to separate from influences calculated to lead away from God.
The verse warns to keep young people away from corrupting places and associations and to guard what they see and hear. The record also encourages those who fall, because through God's grace they can rise again and continue the struggle against sin. They are to take courage from examples of people who struggled, fell, and overcame.