Delivering the sermon standing and sitting between the two sermons

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reports about the Prophet (peace and blessings be upon him) that on Friday he would deliver the sermon standing, then he would sit down, then he would stand up and deliver (the second) sermon.
Ahmad, Abu Ya'la and al-Tabarani in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat recorded it; the narrators of al-Tabarani are thiqat (trustworthy).

In the narration of Imam al-Bazzar the wording is: The Prophet (peace and blessings be upon him) used to deliver two sermons on Friday, separating them by sitting between them.
The narrators of Imam al-Tabarani are the narrators of the Sahih.

Sayyiduna al-Sa'ib bin Yazid narrates: The Prophet (peace and blessings be upon him) used to deliver two sermons for Jumu'ah, and he would sit between the two.
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains a narrator, Ibn Ishaq, who is a mudallis (one who conceals defects in his chain).

Musa bin Talhah narrates: I was present with Sayyiduna Uthman al-Ghani (may Allah be pleased with him); he delivered the sermon standing on the minbar. I was also present with Sayyiduna Mu'awiyah; he delivered the sermon sitting. He said: "I am not unaware of the Sunnah, but my age has advanced, my bones have become weak, and your affairs have become many. So I intended to settle some of your affairs while sitting; then I will stand and take my share of the Sunnah."
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains a narrator, Qays bin al-Rabi', whom Shu'bah and al-Thawri declared thiqah (trustworthy), while others declared him da'if (weak).