I say, and with God's success: It is disliked to perform voluntary prayers during the sermon: such as the Friday sermon, the two Eid sermons, and the sermons during Hajj, whether the prayer is a greeting for the mosque or a Sunnah for Friday; as evidenced by the texts regarding the obligation of listening, and voluntary prayers disrupt listening, and thus cannot contradict the report of a single narrator. Among these is the narration from Ata al-Khurasani, may God have mercy on him, who said: Nabiha al-Hudhali, may God be pleased with him, narrated from the Messenger of God, peace be upon him: "When a Muslim takes a bath on Friday, then comes to the mosque without disturbing anyone, if he does not find the imam, he may pray as he wishes, but if he finds the imam has come out, he should sit and listen and be silent until the imam finishes his Friday prayer and his speech; if he is not forgiven in that Friday, all his sins will be atoned for as a compensation for the previous Friday." This is in Musnad Ahmad 5: 75. Al-Haythami said in Majma' al-Zawa'id 2: 171: "Its narrators are the narrators of the Sahih except for Sheikh Ahmad, who is trustworthy." And because enjoining good is obligatory, and it is prohibited in this case, what do you think about voluntary prayers? Abu Huraira, may God be pleased with him, said the Messenger of God, peace be upon him, said: "If you say to your companion 'Be quiet' on Friday while the imam is giving the sermon, you have engaged in idle talk." This is in Sahih Muslim 2: 583, and Sahih al-Bukhari 1: 316. Ibn Umar, may God be pleased with them, said the Messenger of God, peace be upon him, said: "If one of you enters the mosque while the imam is on the pulpit, there should be no prayer or talking until the imam finishes." This is in Al-Mu'jam al-Kabir 3280, and it was deemed good in I'la al-Sunan 2: 68. This is narrated from Ali, Ibn Abbas, Ibn Umar, and Sa'id ibn al-Musayyib, may God be pleased with them, as they disliked praying and talking after the imam had come out. It was narrated by Ibn Abi Shaybah in his Musannaf 1: 448, 458. And from Thalabah ibn Abi Malik, may God be pleased with him: "They used to pray on Friday until Umar ibn al-Khattab came out..." This was narrated by Muhammad in Al-Muwatta 1: 603. See: Kanz al-Daqaiq with Al-Tabyin 1: 87, Al-Wiqayah p. 138, and 'Umdat al-Ri'ayah 1: 150, and God knows best.