The Rebbe started Mivtza Taharas HaMishpacha to “fix the spiritual decline in recent years.” The first time the Rebbe spoke of the initiative was Tes-Zayin Tammuz 5735.
Sichos Kodesh (Seif Hei) | Likkutei Sichos (Page 259-264) | Audio
On the following Shabbos, Parshas Matos-Masei, the Rebbe “continued the discussion from the previous week,” and encouraged the Chassidim to join the new initiative of Taharas Hamishpacha.
Sichos Kodesh | Likkutei Sichos (Page 295-298)
A few weeks later, on Alef D’Rosh Chodesh Elul, the Rebbe again spoke about the initiative, adding the importance of reaching older women.
Sichos Kodesh (Seif Daled) | Audio
A year later, on Shabbos Parshas Matos-Masei 5736, the Rebbe once again connected the initiative to that week's Sedra, and added that the time has come to fix the issues of the past.
Sichos Kodesh (Seif Vov)
On Rosh Hashanah 5738, the Rebbe connected the idea of Taharas Hamishpacha to Teshuvah.
Sichos Kodesh (Seif Yud Gimmel)
The following year, on Motzei Shabbos Parshas Vayeilech 5739, the Rebbe explained how through adding in purity down here, we are adding in purity L’mailah.
Sichos Kodesh (Seif Chof Gimmel) | Audio | English
The Jewish Home - Volume 1: As Illuminated by the Teachings Of Kabbalah and Chassidus