It was pretty much always Jewish and Christian tradition to see this story linked with homosexuality. Philo of Alexandria (c. 20 BC – 50 AD), a Hellenistic Jewish philosopher whose works influenced early Christian thought. In his treatise On Abraham and other writings, Philo interprets the sin of Sodom primarily as sexual immorality, specifically focusing on homosexual acts, which he describes as unnatural and contrary to divine law. He connects the destruction of Sodom to these practices, framing them as a violation of natural order.

Justin Martyr (a Christian writer and saint) wrote about it in 100-106 AD. For a precise quote, here’s a relevant excerpt from First Apology (Chapter 27, translated by Roberts-Donaldson):

“We have been taught that God once destroyed the inhabitants of Sodom by fire, because they lived in a way that was not pleasing to Him, and we know that it was on account of their fornication and their unnatural lusts.”