Mamoon's Marriage

Al-Ma'mūn gave his wife one million dinars as a dower. It is worth mentioning that the value of a dinar was equal to a camel. Al-Hasan b. Sahl, the father of lady Bourān, stipulated that al-Ma'mūn should marry his daughter in his village situated at Fam al-Sulh[3], and he responded to that. When he wanted to marry her, he traveled to Fam al-Sulh and spent one million dinars on the soldiers who were with him. He took with him thirty thousand young boys and seven hundred slave-girls. As for the soldiers who were with him, they were four hundred thousand horsemen and three hundred thousand infantry soldiers. As for al-Hasan b. Sahl, he slaughtered thirty thousand sheep, a similar number of chicken, four hundred cows, and four hundred camels. The people called this invitation the Invitation of Islam, but this title is wrong, for such extravagance from the money of the Muslims does not belong to Islam. The expenditures of al-Ma'mūn on this marriage were thirty-eight million dinars[1] apart from what he gave to her father, for he gave him ten millions dirhams from the land taxes of Fars (Iran) and the lands of al-Sulh.[2]
Anyhow, when al-Ma'mūn married Bourān, ambergris hazelnuts were scattered from the roof of the house of al-Hasan b. Sahl, but the people disdained them and abstained from them, so a person called out to them, saying: "Whoever has taken a hazelnut, let him break it, for he will find in it a piece of paper on which it has been written either one thousand dinars or ten silk garments or five garments or a retainer or a slave-girl." Those who obtained pieces of paper sent them to the Divan and received what was written on them.[3]Likewise, al-Ma'mūn spent one million dirhams on the commanders of his army.[4] Congratulating al-Hasan b. Sahl, his daughter, and al-Ma'mūn, al-Bāhili said:
May Allah bless al-Hasan and Bourān regarding the
marriage. O son of Hārūn, you have gained, but whose
daughter is she? [5]
When the hour of wedding came, Bourān was seated on a mat made of gold. Then al-Ma'mūn came in to her and he was accompanied by his aunts and a group of the 'Abbāsid women, so al-Hasan b. Sahl scattered three hundred pearls over al-Ma'mūn and his wife. The weight of each pearl was a weight (mithqāl). None stretched out his hand to take them, so al-Ma'mūn ordered his aunts to take them; he stretched out his hand to take one, and thus the 'Abbasid women hurried to take some. 

Reference :The life of Imām'Ali Bin Mūsā al-Ridā