also known as Surah Bani Israel [The Children of Israel]
Ayat 32. And come not near to the unlawful sexual intercourse. Verily, it is a Fâhishah [i.e. anything that transgresses its limits (a great sin)], and an evil way (that leads one to Hell unless Allah forgives him).
Hazrat Ubada bin As-Samit (May Allah be pleased with him) said: I, along with a group of people, gave the pledge of allegiance to The Messenger of Allah [S.A.W.W](PBUH). He said, "I take your Pledge on the condition that you (1) will not join partners in worship with Allah, (2) will not steal, (3) will not commit illegal sexual intercourse, (4) will not kill your offspring (for fear of poverty), (5) will not slander, (6) and will not disobey me when I order you to do good. Whoever among you will abide by his pledge, his reward will be with Allah, and whoever commits any of those sins and receives the punishment in this world, that punishment will be an expiation for his sins and purification; but if Allah screens him, then it will be up to Allah to punish him if He will or excuse Him, if He will."
[Al-Bukhari Book 05, Chapter 58, Hadith # 232].
Lesson : as mentioned above in Surah Al-Isra Ayat 31. "And kill not your children for fear of poverty" This Hadith here the bring forth attention of muslim to their obligations, being fully conscious of their accountability to Allah (SWT) they are apt to make full efforts to provide justice and peace to other people. Shirk (polytheism) is an absolutely unpardonable sin. All other sins, how many and how grave they may be, can be forgiven by Allah. He will pardon them if He likes and send the sinful persons straight to Jannah, or keep them for a while in Hell and then shift them to Jannah. In any case, the punishment of Hell will not be eternal for them, as it is for the Mushriks (polytheist).