Theophylact of Ohrid

The Lord presents the wife of Lot as an example. She, having looked back, became a pillar of salt (Gen. 19:26), that is, not having departed from wickedness, she remained in its saltiness, having become entirely wicked, and, having sunk and remained in evil, she stands as a monument of the defeat which she suffered.

Commentary on Luke ↗

Augustine of Hippo

Lot's wife represents those who in time of trouble look back and turn aside from the hope of the divine promise, and hence she was made a pillar of salt as a warning to men not to do likewise, and to season as it were their hearts, lest they become corrupt.

Catena Aurea by Aquinas ↗

Ambrose of Milan

For this reason, the Lord says, "Remember Lot's wife," who because she looked back, lost the function of her own nature. Satan and Sodom are behind. Flee excess and shun extravagance. Know that not everyone can flee to the mountain. Remember that the one who did not return to his old pursuits, as if to Sodom, escaped because he came to the mountain. She, who was weaker since she looked back, could not come to the mountain. She remained, although her husband's help supported her.

Commentary on Luke ↗

Bede

Remember Lot's wife. Lot's wife signifies those who in tribulation look back and turn away from the hope of God's promise. Therefore, she was made into a pillar of salt, as a warning to people not to do this, as if they season their heart, so that they may not be foolish.

On the Gospel of Luke ↗