17. " verily repentance with allah is only for those who do evil ignorantly and
then repent soon. so, these are they toward whom
allah returns (mercifully) and allah is all-knowing, all-wise."

commentary:
in the previous verse, the subject of the fulfilment of stripes upon
those who commit indecency, fornication, as their punishment with
repentance, was clearly stated. in the above verse, some of its conditions
are mentioned, too. it says:

" verily repentance with allah is only for those who do evil ignorantly..."

the purpose of the usage of the term `ignorantly' in the above
mentioned verse is the violence of instincts and the domination of the
strong low desires, and their conquest over the strength of intellect and
faith. in this state, the knowledge of man about sins, although does not
vanish completely, under the influence of those strong instincts becomes
affected and, actually, remains futile. so, when the knowledge of man loses
its effect, it will practically be equal to ignorance.

in the next sentence, the qur'an has pointed to one of other
conditions of repentance, where it says:

"... and then repent soon. ..."

that is, they regret from their actions soon and return to allah,
since a complete repentance is that which, on the whole, wipes out the
remaining effects of sins from the spirit and mind of the person.
after mentioning the conditions of repentance, the verse concludes
as such:

"... so, these are they toward whom allah returns (mercifully) and allah
is all-knowing, all-wise."