Is the saying of "peace be upon you" by some congregants to one another after the salutation of the obligatory prayer an innovation?

Spreading greetings of peace (salam) is a religious requirement and leads to affection and entry into Paradise. It is from the Sunnah for a Muslim to say salam upon leaving a gathering, as indicated by the noble Hadith: "When one of you comes to a gathering, let him give salam. If it seems good to him to sit, let him sit. Then, if he stands up while the people are still sitting, let him give salam, for the first is no more deserving than the last." There is no text that prohibits giving salam immediately after prayer; rather, it falls under the general permissibility of giving salam when intending to depart, and it is not considered an innovation.