The sin of Lashon HaRa can be performed through inflections in one’s speech which would thereby convey Lashon HaRa, as well as by physical gestures that would indicate the negative.
Therefore, even while reciting the pasuk which recalls Miriam’s punishment for speaking Lashon HaRa, one can involve oneself in Lashon HaRa actively, through gesturing or saying the words with certain inflections or can passively involve oneself in Lashon HaRa by listening to another person relate Lashon HaRa.
 The entire pasuk reads, “For [The Torah] is not an empty matter from you, for it is your lives, and with this thing you shall lengthen your days on the Land which you are crossing the Jordan [River, to go] over there [in order] to inherit it.” (Devarim: 32; 47)
RaSh”I writes on this pasuk, as follows:
“You are not wearying yourselves in [The Torah] for no reason, for there is great reward dependent on [involvement in The Torah], “for it is your lives”. Another explanation, [is as follows]: There is nothing empty in The Torah, concerning which if you would expound it, that you wouldn’t receive a reward [for that]. You should know [that this is the case], for such did the Chachamim (Sages) say [concerning the following pasuk], “and the sister of Lotan was Timna” (B’reishis: 36; 22) “and Timna was a concubine [to Eliphaz, the son of Eisav]” (36; 12) Since [Timna] said, ‘I am not fitting to be his wife, if only I could be his concubine’. Why [did The Torah inform us] of all of this? In order to inform [us] concerning the praise of Avraham, that rulers and kings desired to cling to his descendants.” (Sifrei: 32; 46)
Therefore, as RaSh”I has explained, The Torah is not lacking and is not empty in any regard.
 This teaching that if The Torah is empty, it is only empty on account of the person, can be found in the notes on the commentary of the “Torah T’mimah” (D’varim: 32; 47), where he quotes the Talmud Yerushalmi, maseches “Peah” (Chapter 1; Halacha 1), where Rav Manna teaches that if any matter in The Torah seems to be unclear to the person, it is due to not having put in sufficient effort in studying the given matter that would allow that person to have a clear understading of the topic. In order to make The Torah “our lives” we have to put great effort in our involvement in The Torah (weary ourselves in The Torah).
 The entire pasuk from sefer “Yeshayahu” states as follows:
“HaShem said, ‘Since this nation has approached Me, through their mouth and their lips they have honored Me, and their heart is distant from Me, and their fear of Me will be like the command of those who teach them.” (Yishayhu: 29; 13)
RaSh”I explains that the fear of these people will not be carried out wholeheartedly, rather they behave in accordance with that which they are taught – to approach HaShem while acting submissively in order “to entice” Him with their mouths and their lips, merely acting as if they are honoring HaShem, though their hearts are distant from HaShem.
MaLBI”M explains this pasuk in the context of that which immediately precedes this pasuk (Yeshayahu: 29; 9 – 12), where some people claim that, since HaShem is so lofty, it is impossible to understand the messages that HaShem sends to them. Therefore, these people who act as if they are honoring HaShem by saying that His messages are above our comprehension, are really only honoring HaShem “through their mouths and their lips”, while, in reality, by making such claims, they are effectively distancing their hearts from HaShem. Since, through their claims that it is impossible to comprehend The laws and mitzvos of HaShem, they act as if we only have to outwardly perform the mitzvos, with no thought or kavana (concentration on the action being performed). Therefore, even their fear of HaShem will not complete and genuine, it will rather be that which one has been accustomed to. The MaLBI”M differentiates the aforementioned types of people with those who are accustomed to perform the mitzvos from their youth, though they don’t invest thought and kavana in the performance of the mitzvos, but they believe that the mitzvos come from HaShem. However, in our context, the people who perform the mitzvos out of habituation do so only because they are instructed by their teachers and their parents to do so, not because HaShem commanded them to perform the mitzvos. For due to such claims that HaShem’s laws and messages are impossible to understand, the person will deny that HaShem even commanded people to perform these mitzvos and claim that people are unable to understand the reasons and the intention behind the mitzvos.
Clearly, as this pasuk applies to our context of speaking Lashon HaRa regardless of having remembered concerning the Lashon HaRa that Miriam spoke and her ensuing punishment, they are merely reciting this pasuk with “their mouths and their lips”, due to their being accustomed to recite this pasuk, though they lack the proper kavana, and thereby do not recite the pasuk wholeheartedly. Therefore, due to the lacking of the person who is reciting this pasuk, they can so easily involve themselves in Lashon HaRa though they have just verbalized concerning the greatness of the sin of Lashon HaRa and of its ensuing punishment.