What is the Sharia ruling on a married woman who betrayed her husband and entered into a relationship with another man, and who claims to have repented and to regret what she did?

The woman committed forbidden acts by speaking to a foreign man, being submissive to him, engaging in a sinful relationship with him, and allowing him into her husband's house and to be in seclusion with her. This violates Allah Almighty's saying: ﴿So do not be soft in speech [to men], lest he in whose heart is disease should covet, but speak with appropriate speech.﴾.

If she repents sincerely, regrets, and resolves not to return to such acts, then her repentance is hoped to be accepted, for Allah Almighty says: ﴿But indeed, I am the Forgiving to whoever repents, believes, and does righteousness, and then is guided.﴾. She must increase in good deeds, seek forgiveness, and conceal herself. If the husband becomes aware of some of this and believes in her sincerity of repentance, then it is preferable for him to forgive her and not punish her. For that, he will have a reward from Allah, as the Prophet (peace be upon him) said: "Whoever conceals a Muslim, Allah will conceal him on the Day of Resurrection."