What are the sayings of the scholars regarding the invalidation of the prostration of forgetfulness due to a long separation, speech, or ritual impurity, and is it invalidated by the entry of the time for another prayer, or is it never invalidated, and what is the most preponderant opinion with evidence?

Scholars have differed on whether the prostration of forgetfulness (sujood al-sahw) is waived by a long interval (between the forgetfulness and the prostration). The majority opinion is that it is waived. However, the Malikis distinguished between the pre-salaam prostration (qabli) and the post-salaam prostration (ba'di). They stated that the pre-salaam prostration is waived by a long interval, but the post-salaam prostration is not waived, even if the interval extends for years. The duty of a layperson is to emulate whomever among the people of knowledge they trust.