It is narrated from Ibn Abbas (may Allah be pleased with them) that he said: A marriage does not take place without a guardian, a wali, and two trustworthy witnesses.
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1133
Hadith Takhrijصحيح بطرقه اخرجه البيهقي: 7 / 112، 124، 126 - وعبد الرزاق (10483) وابن ابي شيبة (15917)۔
It is narrated from Ibn Abbas (may Allah be pleased with them) that he stated: A marriage does not take place without a guardian, two trustworthy witnesses, and a guiding guardian, and in my opinion, Muslim heard this from Ibn Khuthaym.
Hadith Referenceمسند الإمام الشافعي / كتاب النكاح / 1134
Hadith Takhrijسنده قوی اخرجه البيهقى 126/7 - وفى المعرفة السنن والآثار له (4076)۔