Question: May Allah preserve you, do the Scholars determine or enumerate the sects which come in the Hadith about seventy three sects? And are the Jahmiyyah part of the seventy three sects?
Answer: “The Scholars mention the origin of these sects. As for the Jahmiyyah, then some of the People of Knowledge did not count them as not being part of the seventy two sects. This is because the seventy two sects are from the Ummatul-Ijaabah (the nation who answered the call). They are from the Muslims. So like this, some of the Scholars or a group from the Scholars have declared the Jahmiyyah as disbelievers. They said they are outside the seventy two sects and not part of the seventy two sects which are Islamic sects”
[Sharh Sunan Nasaai no. 371]
Faisal Ibn Abdul Qaadir Ibn Hassan