Ibn Shihab (may Allah have mercy on him) narrates, concerning the two who performed li'an, from Sayyiduna Sahl bin Sa'd al-Sa'idi (may Allah be pleased with him), one of Banu Sa'idah, that a man of the Ansar said: O Messenger of Allah (peace and blessings be upon him)! If someone sees a man with his wife, what should he do? Then the verses of li'an were revealed concerning him, and the Messenger of Allah (peace and blessings be upon him) said: "Allah has given judgement concerning you and your wife." The narrator says: They performed li'an in the mosque, and I was present.
(b) Ibn Shihab (may Allah have mercy on him) narrates from Sayyiduna Sahl (may Allah be pleased with him) in this hadith that the two of them performed li'an, and I was present among the people.
(c) Yunus (may Allah have mercy on him) narrates from Ibn Shihab (may Allah have mercy on him) or someone else that the Messenger of Allah (peace and blessings be upon him) ordered the husband and wife to swear oaths after Asr near the pulpit.
This is munqati' (broken); it has reached us with a connected chain only through Muhammad bin Umar al-Waqidi, and he is da'if (weak).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15305
Sayyiduna Abdullah bin Ja'far (may Allah be pleased with him) says: When Uwaymir al-Ajlani performed li'an with his wife, I was with the Messenger of Allah (peace and blessings be upon him). On the return from Tabuk, Uwaymir had denied his wife's pregnancy; he said: This pregnancy is from Ibn al-Sahma'. The Messenger of Allah (peace and blessings be upon him) said: "Bring your wife; the Qur'an has been revealed concerning the two of you." Then the two of them performed li'an after Asr near the pulpit, concerning the pregnancy.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15306
وَأَخْبَرَنَا أَبُو بَكْرٍ، أنا عَلِيٌّ، نا أَحْمَدُ بْنُ عِيسَى الْخَوَّاصُ، نا مُحَمَّدُ بْنُ سَعْدٍ الْعَوْفِيُّ، نا الْوَاقِدِيُّ، بِهَذَا الْإِسْنَادِ نَحْوَهُ.
Likewise (through another chain, from al-Waqidi, with this same chain), with similar wording.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15307
Jabir bin Abdullah al-Sulami (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "Whoever swears a false oath at this pulpit of mine, let him take his seat in Hellfire."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15308
Jabir bin Abdullah (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "Whoever swears a false oath at my pulpit, even over a green tooth-stick (miswak), let him take his seat in Hellfire."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15309