There were several ceremonies leading up to the actual wedding of Amir and Soraya. First came the lafz ("the ceremony of 'giving word' ") at the general's home before several dozen guests, with Soraya making her appearance at the end. They skipped the traditional Shirini-kori ("the 'Eating of the Sweets' cermony") because of Baba's illness. Baba spent most of the money he had saved (more than $30,000) on the nika, the "swearing ceremony." The wedding couple dressed in traditional green, a symbol of "new beginnings." Many of the guests spoke before Amir and Soraya approached the stage, followed by "a procession of uncles, aunts and cousins." The Afghanistan "wedding song, ahesta boro, blared from the speakers." Then followed Ayena Masshaf, a ceremony involving mirrors in order for the couple to "gaze at each other's reflection." They danced the attan, a circle dance, before
... the party moved from the banquet hall to Baba's apartment... until the neighbors called the cops. (Chapter 13)
You can find a detailed description in Chapter 13 of the novel.