Ṭūbā conveys blessedness and a happy outcome. The promise concerns a person who finds much istighfār in their record. The narration specifies no exact daily number, so a particular count should not be attributed to its wording.
A practical self-review might ask: Did I harm someone with my words? Did I neglect another person's rights? What can I correct? Requesting Allah's forgiveness can accompany real steps toward improvement.
وَجَدَ is a past-tense verb, “he found.” It evokes a person discovering what has been recorded of their actions.