The Abbasides conquered K͟horasan under the brothers Ibrāhīm and Abū ʾl-ʿAbbās, and refused to acknowledge Marwān. Marwān was afterwards defeated on the banks of the Zab, and fled to Egypt, where he was again defeated and slain, A.H. 132 (A.D. 750), and Abū ʾl-ʿAbbās was proclaimed K͟halīfah. [[KHALIFAH].]

OPTION. [[KHIYAR].]

ORDINATION. There is no ceremony in Islām corresponding to the Christian ordination. Sometimes the Imām of a mosque is appointed by the chief man of position binding a turban round his head. In Central Asia, Maulawīs of reputation certify as to the learning and ability of their disciples by binding a turban on their heads and authorizing them to teach. But it is not a custom of the Muslim religion.

ORNAMENTS. Men are prohibited from the use of ornaments of gold, such as rings and the like, because they are expressly forbidden by the Prophet. Ornaments of silver are likewise unlawful, but exceptions are made with respect to signet rings, girdles, or swords, which may be ornamented with silver. (Hidāyah, vol. iv. p. 92). Ibn Zubair says the Prophet condemned the use of little bells as ornaments for children, for he said there was a devil in every bell. Ibn Mālik says the Prophet forbade the wearing of gold rings, and he considered it just as bad to use gold ornaments. (Mishkāt, book xx. ch. ii.)

The Wahhābīs condemn the use of ornaments and silk dresses.

ORPHANS. Arabic yatīm (يتيم‎), pl. yatāmā. In Muḥammadan law, the term is used for a child whose father is dead.

Muḥammad gave very special instructions in the Qurʾān as to the treatment of orphans. See [Sūrah iv. 2–7]:—

“And give to the orphans their property and substitute not worthless things of your own for their valuable ones, and enjoy not their property in addition to your own; verily this is a great crime: and if ye are apprehensive that ye shall not deal fairly with orphans, then, of other women who seem good in your eyes, marry but two, or three, or four; and if ye still fear that ye shall not act equitably, then one only, or the slaves whom ye have acquired; this will make justice on your part easier. And give women their dowry as a free gift; but if of their own free will they kindly give up aught thereof to you, then enjoy it as convenient and profitable. And entrust not to the incapable the substance which God hath placed with you as a means of support, but maintain them therewith; and clothe them, and speak to them with kindly speech. And make trial of orphans until they reach the age of marriage; and if ye perceive in them a sound judgment, then hand over their substance to them; but consume ye it not profusely and hastily. Only because they have attained their majority. And let the rich guardian not even touch it; and let him who is poor, then use it for his support with discretion. And when ye make over their substance to them, then take witnesses in their presence. God also taketh a sufficient account.”

According to al-Baiẓāwī and the Jalālān, the Muslim commentators understand these verses differently. Mr. Sale says the true meaning seems to be: Muḥammad, advising his followers that if they found they should wrong the female orphans under their care, either by marrying them against their inclinations, for the sake of their riches or beauty, or by not using or maintaining them so well as they ought by reason of their having already several wives, they should rather choose to marry other women, to avoid all occasion of sin. Others say that when this passage was revealed, many of the Arabians, fearing trouble and temptation, refused to take upon them the charge of orphans, and yet multiplied wives to a great excess and used them ill or, as others write, gave themselves up to fornication, which occasioned the passage. And according to these, its meaning must be either that if they feared they could not act justly towards orphans, they had as great reason to apprehend they could not deal equitably with so many wives, and therefore are commanded to marry but a certain number; or else, that since fornication was a crime as well as a wronging of orphans, they ought to avoid that also by marrying according to their abilities.

OTHMAN. [[ʿUSMAN].]