Is inserting a finger into the vagina considered fornication, like sexual intercourse?

Adultery (zina) is a major sin. The type of adultery that necessitates a prescribed punishment (hadd) is the insertion of a man's penis into a woman's vagina when she is unlawful to him. What was mentioned about the woman with the foreign man is not considered adultery that necessitates a hadd punishment, but it is a great sin. It falls under the category of "zina" that the Prophet, peace and blessings be upon him, referred to when he said: "The two eyes commit zina by gazing, the two ears commit zina by listening, the tongue commits zina by speaking, the hand commits zina by seizing, the two feet commit zina by stepping, and the heart desires and wishes, and the private part confirms or denies that." These actions are forbidden, a betrayal of the husband's trust, and evidence of weak faith and lack of modesty. She must repent by ceasing the sin, feeling remorse, and resolving not to return to it, adhering to the limits of the Sharia (definition), and increasing in good deeds, while concealing herself and being wary of publicizing it. Otherwise, she must be shunned and companionship with her abandoned.