Is repentance from sins obligatory immediately without being certain of their intentional commission, and is repentance accepted if intentionality is not ascertained?

Sincere repentance, which encompasses and erases all sins — by Allah's permission — is accepted from a servant, whether he knows about the sin or is ignorant of it. One should abandon obsessive thoughts concerning this matter. For Allah accepts repentance from His servants and pardons evil deeds.