How to sit in the first and second tashahhud

It is narrated from Muhammad bin Amr bin Ata that he was sitting in a group of the Companions of the Messenger of Allah (peace and blessings be upon him) when the prayer of the Messenger of Allah (peace and blessings be upon him) came to be mentioned. Abu Humayd al-Sa'idi (may Allah be pleased with him) said: I am the one among you who best remembers the prayer of the Messenger of Allah (peace and blessings be upon him). I saw him: when he (peace and blessings be upon him) said the takbir, he would raise his hands level with his shoulders; when he bowed, he would rest his hands firmly on his knees and bend his back; then when he raised his blessed head from bowing, he would stand up straight until every joint reached its place; when he prostrated, he would place his hands on the ground, neither spread out too far nor drawn in; and he would point the tips of his toes towards the qiblah; when he sat after two rak'ahs, he would lay his legs down, then sit on his left leg; and when he sat in the final sitting, he would lay his left foot down and sit on his buttocks.

(a) In another chain it is narrated from Muhammad bin Amr bin Ata that he was sitting in a group of the noble Companions of the Messenger of Allah (peace and blessings be upon him) (may Allah be pleased with them), and then he mentioned the complete hadith.
(b) Imam al-Bayhaqi (may Allah have mercy on him) said: Imam al-Bukhari (may Allah have mercy on him) says (in his narration) that he pointed the tips of his toes towards the qiblah; then when he sat after two rak'ahs, he sat on his left leg and kept his right foot upright; and when he sat in the final sitting, he laid his left foot down, kept his right foot upright and sat on his buttocks.

Shababah bin Sawwar (may Allah have mercy on him) relates in this narration that when the Prophet (peace and blessings be upon him) sat in the first two rak'ahs, he would sit on his left foot and keep his right foot upright; and when he sat in the final rak'ah, he would sit on his buttocks, bring the inner part (sole) of his left foot close to the back of the knee of his right thigh, and keep his right foot upright.

It is reported from Muhammad bin Amr bin Ata that Sayyiduna Abu Humayd al-Sa'idi (may Allah be pleased with him) said: I saw the Messenger of Allah (peace and blessings be upon him): when he sat after two rak'ahs (the first sitting), he would sit on the sole of his left foot and keep his right foot upright; and when he sat after the fourth rak'ah, he would place his left hip on the ground and bring both his feet out to the right side.

Abbas bin Sahl said: Once Abu Humayd, Abu Usayd, Sahl bin Sa'd and Muhammad bin Maslamah (may Allah be pleased with them) gathered together and mentioned the prayer of the Messenger of Allah (peace and blessings be upon 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 mentioned that he (peace and blessings be upon him) then sat (after finishing the second prostration), laid down his left foot and kept the front of his right foot facing the qiblah; then he placed his right palm on his right knee and his left palm on his left knee, and pointed with his index finger.
This is about his (peace and blessings be upon him) first tashahhud; there is no mention of the second tashahhud in this hadith.

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).

It is narrated from Ubaydullah bin Abdullah bin Umar that he saw Abdullah bin Umar (may Allah be pleased with them both) sitting cross-legged in prayer when he sat. I too sat in the same way, and I was young in those days. Abdullah bin Umar (may Allah be pleased with them both) forbade me and said: The Sunnah way of sitting in prayer is that you keep your right foot upright and lay the left one down and sit on it. I asked: But you do it this way (cross-legged)? He said: My feet cannot bear my weight (that is, I am unwell).

Abdullah bin Abdullah bin Umar narrates from his father (may Allah be pleased with them both) that: "The Sunnah of prayer is that one keeps the right foot upright and lays the left foot flat."

It is narrated from Yahya bin Sa'id (may Allah have mercy on him) that when al-Qasim bin Muhammad (may Allah have mercy on him) sat in the tashahhud, he would keep his right foot upright, lay his left foot flat, sit on his left hip, and not sit on his feet. And he would say: I saw Abdullah bin Abdullah bin Umar (may Allah be pleased with them both), and he narrated to me that his father used to do the same.