The second form: Al-Bukhārī recorded it in his Sahīh (1), in (2) another hadith of Abū Humayd, who said: “When he sat in the final rak‘ah (3), he brought his left foot forward, kept his right foot upright, and sat on his buttocks.” This agrees with the first description in having him sit on his hip, but adds details about the position of the feet that the first narration did not address.
The third form: Muslim recorded in his Sahīh (4), in the hadith of ‘Abd Allāh ibn al-Zubayr, that the Prophet, peace and blessings be upon him, would place his left foot between his thigh and lower leg and lay his right foot flat. This is the posture chosen by Abū al-Qāsim al-Khiraqī in his Mukhtasar (5). It differs from the first two descriptions regarding the extension of the left foot to one side and keeping the right foot upright. Perhaps (6) he adopted one posture on some occasions and the other on others; this is the more likely explanation. It is also possible that the difference arose from variations among the narrators.
This posture of sitting on the hip was reported from him, peace and blessings be upon him, only in the tashahhud immediately before the closing salutation. Imām Ahmad and those who agreed with him then stated: This applies specifically to prayers containing two tashahhuds. In such prayers, this posture serves to distinguish between sitting for the first tashahhud, which it is recommended (7) to keep brief,