What is the criterion for reviving the Sunnah and distinguishing it from religious innovation?

Question:
Does the prescribed Sunnah include the Sunnah that was revived after it had previously died out, and the Sunnah that is being newly revived?

Answer:
Generally, it includes the Sunnah that he revived, or that died out and then he revived.
The point is that in a country, village, desert, or settlement, there is a dead Sunnah and he revives it. For example, they did not know the Duha prayer, so he began praying Duha. Or they did not pray before the Asr prayer, so he prayed four rak'ahs before Asr. Or they did not announce the marriage and did not hold a wedding feast for it, so he announced the marriage, and so on.
Q: Is there a person who revives a new Sunnah?
A: It may be that in some regions, a Sunnah is new, meaning it had been abandoned. It may be that in some regions, people did not know, for example, the Duha prayer, or did not know, for example, the manner of Hajj, and where Hajj is: in Makkah or elsewhere? So he came and taught them and revived the Sunnah for them. Or they did not know dutifulness to parents, or maintaining family ties, or the Witr prayer, and so on.
Q: Is it called "new"?
A: This is the revival of the Sunnahs.
Q: Because he says: "a new Sunnah"?
A: The meaning is its revival; it is not a religious innovation. A new religious innovation is not called a Sunnah. The point is meaning: he revived it and made it manifest. This is the matter. Otherwise, if he initiates it, it becomes a religious innovation.