Muhammad bin Amr bin Ata (may Allah have mercy on him) said that Abu Humayd al-Sa'idi (may Allah be pleased with him) was sitting among ten of the noble Companions (may Allah be pleased with them), among whom was Abu Qatadah (may Allah be pleased with him). Abu Humayd (may Allah be pleased with him) said: I know more than all of you about the prayer of the Messenger of Allah (peace and blessings be upon him). In it, it is also mentioned that when he (peace and blessings be upon him) was in the final rak'ah, he would bring his left foot out (from under the buttocks to the right side) and sit on his left hip; and they all said: You have spoken the truth, the Messenger of Allah (peace and blessings be upon him) did indeed pray like this.
(b) This hadith is explicit about the final tashahhud. It does not describe the manner of sitting in the first tashahhud. Ibn Halhalah (may Allah have mercy on him) preserved both of them together from Muhammad bin Amr (may Allah have mercy on him).
(c) In the hadith of Abu al-Jawza' (may Allah have mercy on him) it is reported from Sayyidah Aishah (may Allah be pleased with her) about the prayer of the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) would recite the tashahhud after two rak'ahs, lay his left foot down and keep the right one upright, and he (peace and blessings be upon him) used to forbid "sitting like Satan".
(d) The hadith of Wa'il bin Hujr (may Allah be pleased with him) about the prayer of the Prophet (peace and blessings be upon him) says that he (peace and blessings be upon him) then sat and laid his left leg down.
(e) One of these two is reported about the second tashahhud and the other about the first tashahhud. (This is what is understood) by drawing evidence from the hadith of Abu Humayd al-Sa'idi (may Allah be pleased with him) and the other Companions (may Allah be pleased with them).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2775