Some information regarding Hadith

Sulaassi is a Hadith which has only 3 narrators between the Imam who narrated this Hadith and Rasulullah (Sallallaahu Alaihi Wasallam).

Sunaa-i is a Hadith which has only 2 narrators between the Imam who narrated this Hadith and Rasulullah (Sallallaahu Alaihi Wasallam).

There are 22 Sulaassiyyaat (plural of Sulaasi) in the Bukhari Shareef.

Among the 22 Sulaassiyyaat, there are 20 of it which Imam Bukhari (Rahmatul-laahi 'alayh) narrated from the student of Imam Abu Hanifah (Rahmatul-laahi 'alayh).

The fact that Imam Abu Hanifah (Rahmatul-laahi 'alayh) was very close to Rasulullah (Sallallaahu Alaihi Wasallam), he narrated many Sulaassiyyaat Hadith and he had the chance to narrate Sunaaiyyaat as well.

[English version of "Quelques informations lor hadices" – Al Jamiat – Vol.1 No.10]