Islam strictly prohibits Zina and blocks all doors that may lead to it. In this context, the Prophet Mohammad, peace and blessings are upon him, considered:
Hungry and lustful looks at a person of the opposite sex as "the Zina of the eye," according to his saying, "The eyes also commit Zina, and their Zina is the lustful look." [Reported by Al-Bukhari]
He termed the lustful look Zina because it gives sexual pleasure and gratification in an unlawful way. Indeed, such hungry and lustful looks are not merely a danger to chastity but they also result in agitation of the mind and disturbed thoughts.
This is also what Jesus, peace and blessings are upon him, said in the Gospel of Matthew: “You have heard that it was said, 'You shall not commit adultery'. But I say to you that everyone who so much as looks at woman with evil desire for her has already committed adultery with her in his heart.” [Matt. 5: 2728]
Sheikh Yusuf Al-Qaradawi, states:
“It is not surprising that all the revealed religions have prohibited fornication and adultery [Zina] and have fought against these crimes against society. Islam, the last of the divinely revealed religions, is very strict in prohibiting Zina, for it leads to confusion of lineage, child abuse, the breaking-up of families, bitterness in relationships, the spread of venereal diseases, and a general laxity in morals; moreover, it opens the door to a flood of lusts and self-gratification.
Islam has taken a firm and decisive stance against fornication or adultery [Zina]. Allah in explicit and unequivocal words, commands us:
And come not near unto adultery. Lo! It is an abomination and an evil way. [Al-Israa’: 32]
Islam not only prohibits Zina, but also closes all the avenues and means leading to it. This is achieve by prohibiting every step and means leading to stimulating desires, opening ways for illicit sexual relations between men and women, and promoting indecency and obscenity.
Sheikh Sayyed Sabiq in his book Fiqh As-Sunnah, stated:
“Any illegal sexual intercourse between a man and a woman is subject to a severe punishment prescribed by the Shari’ah. The Fuqahaa’ [Muslim jurists] have unanimously agreed that Zina is constituted by the penetration of the penis into a ‘forbidden’ vagina, deliberately [i.e. not being forced to], and with no doubt of marriage i.e. marriage that is deemed invalid but the couple do not know, even if there is no ejaculation”.
As for other sexual acts of foreplay, which do not result in intercourse, there is no Hadd [prescribed punishment] for it as in the case of Zina. However, the Muslim ruler or judge has the right to give Ta’zeer [disciplinary punishment] for those who indulge in those forbidden activities.
Those acts are not subject to the punishment of Zina.
A Hadith reported by Ibn Mas’ood, which stated:
A man came to the Prophet Muhammad, pbuh, and said: “O Messenger of Allah, I sported with a woman in the outskirts of Madina . . . [and] committed an offence, short of fornication. . . kindly deliver verdict on me.
[i.] Saidina `Umar, who was present, said to him: “Allah concealed your fault. You had better conceal it yourself also.”
[ii.] The Prophet Muhammad, pbuh, gave no reply to him, so the man stood up and went away. Thereupon the Prophet, pbuh, sent a person after him to call on him and recite to him: “And keep up prayer in the two parts of the day and in the first hours of the night; surely good deeds take away evil deeds this is a reminder to the mindful.” [Hud 11:115] Following this, the Prophet, pbuh, dismissed the man, telling him: “Allah has exempted you from the imposition of Hadd, or from your sin.”
[iii.] Someone present at the time asked the Prophet, pbuh, whether such clemency related only to that individual. “No, but for the people at large,” the Prophet, peace and blessings be upon him, said reassuring all believers.”
[Muslim, At-Tarmidzi and Abu Dawood.]
This does not mean that other behaviors such as kissing, hugging, caressing, heavy petting, etc are not major Zina, but they fit into the category of minor Zina, which also is prohibited. Obviously, couples can engage in all these activities without exposed to witnesses and thus avoid punishment in this life. Nevertheless, they still must answer to Allah, the Almighty, who, clearly, admonishes against any sexual contact outside of marriage.
Masturbation is Haram [forbidden] though it is not subject to the same punishment of Zina, 100 lashes for unmarried person; stoning to death to the married one. A person who indulges in these activities should make sincere repentance to Allah by giving up this sin, feeling regretful for what he has done and ask Allah to forgive him.
May Allah protect us from this evil act and guide us on the right path always.