Immoral
وَلَا تَقْرَبُوا الزِّنَا ۖ إِنَّهُ كَانَ فَاحِشَةً وَسَاءَ سَبِيلًا {32}
And do not go near the adultery; it was always an immorality and an evil way [17:32]
ثم قال: و في رواية أبي الجارود، عن أبي جعفر (عليه السلام) في قوله: وَ لا تَقْرَبُوا الزِّنى إِنَّهُ كانَ فاحِشَةً. يقول: «معصية و مقتا، فإن الله يمقته و يبغضه، و قوله: وَ ساءَ سَبِيلًا و هو أشد الناس عذابا، و الزنا من أكبر الكبائر
Then he (Ali Bin Ibrahim) said, ‘And in a report of Abu Al Jaroud,
(It has been narrated) from Abu Ja’far-asws regarding His-azwj Words: And do not go near the adultery; it was always an immorality. He-asws said: ‘A disobedience and an abomination, for Allah-azwj Abhors it and Hates it. And His-azwj Words: and an evil way – and it (deserves) the harshest of the Punishment for the people. And the adultery is the biggest of the major sins’.[1]
[1] تفسير القمّي 2: 19