Currently reading a brilliant kitab by Faqih Abu Lais Samarqandi (A.R.), titled "Admonition for the Neglectful" (Original version: 'Tambhi ul Gafileen'). Many Sufi Scholars use this book for their mureeds (disciples) spiritual upbringing (as mentioned in the 'Forward'.)
I've scanned a small extract from the kitab:
The Tauba of the previous ummahs (nations) was that Allah made a halaal thing haraam due to their sins. Allah also used to write their sin on their doors or on their limbs.
However, Allah has been extremely bountiful to the ummah of Rasulullaah (sallAllaahu-alaihi-wasallam) by not exposing their sins in this manner.
Whenever the sinner turns to Allah asking for forgiveness, Allah says, “My slave has sinned and has realized that he has a Rabb Who is Forgiving and Who has the power to take him to task.” Allah then forgives the person.
Allah says, “Whoever commits a sin or oppresses himself, and then seeks forgiveness from Allah, he shall find Allah to be Most Forgiving, Most Merciful.” A person should repent every morning and evening for his sins.
[From: Admonition for the Neglectful; by Faqih Abu Lais Samarqandi (A.R.)
Translation edited by: Mufti A.H. Elias]