2. Hilchos Eidim
(The Laws of Witnesses)

שלחן ערוך חושן משפט סימן ל”ג, אבן העזר סימן מ”ב

One of the most fundamental and important elements of a marriage – ensuring the halachic acceptability of the witnesses, exploring who may or may not serve as a witness, and what they do at the wedding.