She did something haraam and now a righteous man has come to propose marriage to her but she feels guilty

Question

Praise be to Allah.

Firstly:

Verily to
Allaah we belong and unto Him is our return. This is the result of free
mixing and negligence with regard to the matter of forming haraam
relationships between men and women. How often has this negligence led us
into calamity, regret and sorrow which afflict the one who has lost her
honour, then the wolf drops her beside the road because she is no longer
suitable for his use; there is no way that he will trust her when she agreed
to commit immoral actions with him and he is not prepared to get married at
all, rather his goal is cheap pleasure and spending time with the poor,
heedless woman.

Her family
will be afflicted by the calamity of losing honour if her relationship
becomes known, and every believer in whose heart is any modesty will feel
sad when he hears of such stories. The entire society in which immorality
and evil are widespread will also be affected.

Secondly:

We praise
Allaah that you have repented from these evil actions, and we ask Him to
accept your repentance and to forgive you, and to divert evil and immorality
away from you. But what happened to you is a lesson to others. How often the
scholars and daa’iyahs have warned of the fitnah that men face in women, and
that women face in men, and have spoken of the importance of adhering to the
sacred limits set by Allaah with regard to speaking, listening, looking,
shaking hands and being alone with a member of the opposite sex, so that
honour will be preserved and chastity maintained at a time when the
advocates of immorality are taking such matters lightly and promoting them,
and calling them liberation, civility and progress. The matter is as Allaah
says (interpretation of the meaning):

“Allaah
wishes to accept your repentance, but those who follow their lusts, wish
that you (believers) should deviate tremendously away (from the Right Path)”

[al-Nisa’
4:27].

It is
important that you continue to repent and regret what you have done, and
beseech Allaah a great deal and turn to Him, so that Allaah may forgive you
and conceal your sin in this world and the next.

There is
nothing wrong with you accepting marriage to this pious man who has come to
propose marriage to you, so long as you have repented to Allaah from what
you have done. You do not have to tell him anything about the past, rather
it is not permissible for you to tell him. Conceal yourself with the
concealment of Allaah, as the Prophet (peace and blessings of Allaah be
upon him) said: “Avoid these filthy actions that Allaah has forbidden, and
whoever commits any of them let him conceal himself with the concealment of
Allaah, may He be glorified and exalted.” Narrated by al-Bayhaqi and classed
as saheeh by al-Albaani in al-Silsilah al-Saheehah, no. 663.

Muslim
(2590) narrated from Abu Hurayrah (may Allaah be pleased with him) that the
Prophet (peace and blessings of Allaah be upon him) said: “Allaah does
not conceal a person in this world but Allaah will also conceal him on the
Day of Resurrection.”

This is glad
tidings for the one who repents and is concealed by Allaah in this world:
that Allaah will also conceal him in the Hereafter. What matters is that
does not persist in the sin and does not take advantage of the forgiveness
and forbearance of Allaah, for if Allaah willed, He could expose his sin,
for Allaah gives respite but does not forget.

And Allaah
knows best.