Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "There is no marriage without a guardian." Sulayman bin Dawud is alone in narrating it from al-Nu'man bin Abd al-Salam.
It has been narrated from Mu'ammal bin Isma'il and Bishr bin Mansur from al-Thawri as connected, and from Yazid bin Zuray' from Shu'bah as connected, but what is preserved (mahfuz) from both of them is that it is not connected; reliance is on the narration of Isra'il mentioned earlier and of those who corroborated him in narrating the hadith as connected, and Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13630