Consequently, from all [of that which we have learned], we will understand that each Jewish [person] needs to know the specifics of the laws of Lashon HaRa, in order that he will know [how] to be careful [in his avoidance of involvement in Lashon HaRa. It is essential that the person be familiar with the laws of Lashon HaRa], for [if the person is unfamiliar with some of the laws of Lashon HaRa, of] what benefit will [be gained by] remembering the incident involving Miriam? [For] if the evil inclination entices [the person to speak that which is forbidden, arguing] that this speech does not enter into the category of Lashon HaRa, or that concerning such a person The Torah did not command [one to refrain from when discussing] the prohibition of Lashon HaRa, [how could he be confident that he won’t come to involve himself in the sin of Lashon HaRa]?
 “Kal Va'Chomer” is an a fortiori argument.
 By saying that “we are like moss on the wall compared to Miriam”, the Chofetz Chaim is describing Miriam’s greatness and righteous compared to us.
 This refers to the incident where Moshe sent twelve spies to spy out what would become The Land of Israel, ten of whom spoke Lashon HaRa (and Motzi Shem Ra) about The Land of Israel, the exceptions being Yehoshua and Kalev. This incident is recorded in the beginning of Parshas “Sh’lach” (Bamidbar: 13).
 The fifth chapter of the first volume – “Sha’ar HaZechirah” – begins with the 25th day of Tishrei. The sixth chapter ends with the 30th day of Tishrei.
 As we learned previously, notwithstanding Miriam’s great righteousness and her positive intentions when she spoke the Lashon HaRa, she was punished immediately. How much more so, would the punishment not be delayed for a person who speaks Lashon HaRa with negative intentions and is on a much lower level than Miriam.