Abdullah bin Abbas reported,
The Messenger of Allah ﷺ said, "The expiation of a sin is regret."The Messenger of Allah ﷺ also said, "If you did not sin, Allah 
would bring forth a people who sin so that He may forgive them."
Ahmad 2623
Daifحدثنا أحمد بن عبد الملك الحراني قال حدثنا يحيى بن عمرو بن مالك النكري قال سمعت أبي يحدث عن أبي الجوزاء
عن ابن عباس قال
قال رسول الله ﷺ كفارة الذنب الندامة وقال رسول الله ﷺ لو لم تذنبوا لجاء الله عز وجل بقوم يذنبون ليغفر لهم
Its isnad is daif. Yahya bin Amr bin Malik Nakri is daif, deemed daif by Ibn Main, Abu Zura, Abu Dawud, Nasai, and others, and Hammad bin Zayd accused him of lying. Ahmad said, "He is nothing." Bukhari included his biography in al-Kabir 4/2/292 without mentioning any criticism of him, and did not mention him among the daif narrators.Abu Amr bin Malik was mentioned by Ibn Hibban among the trustworthy narrators, who said, "His hadith is to be considered when not narrated through his son from him. He makes mistakes and reports unusual things." Ibn Abu Hatim included his biography in 3/1/259 without mentioning any criticism of him, and neither Bukhari nor Nasai mentioned him among the daif narrators.Abu Jawza is Aws bin Abdullah Rubai, with the ba pronounced with a fatha. He was a Basran successor, trustworthy, and the authors of the six books narrated from him. Bukhari included his biography in al-Kabir 1/2/17-18 without mentioning any criticism of him, and mentioned a report narrated from him through Amr bin Malik Nakri, then said, "There is something questionable in its isnad," meaning this very isnad. Some people mistakenly thought this was a criticism of Abu Jawza himself, but Ibn Hibban clarified the correct understanding of this, as we have stated.Dhahabi mentioned this hadith in al-Mizan 3:299 and classed it among the objectionable narrations of Yahya bin Amr. Haythami mentioned it in Majma al-Zawaid 10:215, attributing it to Ahmad and to Tabarani in al-Kabir in abridged form, as well as al-Awsat and Bazzar, and said, "It contains Yahya bin Amr bin Malik Nakri, who is daif, though he has also been deemed trustworthy by some, and the rest of its narrators are trustworthy." He also mentioned the first part of it in 10:199, attributing it to Ahmad and to Tabarani in al-Kabir and al-Awsat, and said, "It contains Yahya bin Amr bin Malik Nakri, who is daif."Nakri is spelled with damma on the nun, sukun on the kaf, and ends with ra, and it is a designation referring to the tribe of Nakrah, from the tribe of Abdul-Qays.