Sayyiduna Shaddad bin Shurahbil (may Allah be pleased with him) narrates: I have not forgotten, and I have not forgotten this, that I saw the Prophet (peace and blessings be upon him) standing, having placed his right hand over his left hand and holding it. The narrator says: That is, he did so during prayer.
Al-Bazzar and al-Tabarani in al-Mu'jam al-Kabir recorded it. Its chain contains a narrator Abbas bin Yunus, and I have not found anyone who gives his biography. Al-Bazzar says: Shaddad bin Shurahbil narrated only this hadith from the Prophet (peace and blessings be upon him).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2608