In the seventh century of the Christian era, a wandering Arab of the lineage of Hagar, the Egyptian, combining the powers of transcendent genius, with the preternatural energy of a fanatic, and the fraudulent spirit of an impostor, proclaimed himself as a messenger from Heaven, and spread desolation and delusion over an extensive portion of the earth. Adopting from the sublime conception of the Mosaic law, the doctrine of one omnipotent God; he connected indissolubly with it, the audacious falsehood, that he was himself his prophet and apostle. Adopting from the new Revelation of Jesus, the faith and hope of immortal life, and of future retribution, he humbled it to the dust by adapting all the rewards and sanctions of his religion to the gratification of the sexual passion. He poisoned the sources of human felicity at the fountain, by degrading the condition of the female sex, and the allowance of polygamy; and he declared undistinguishing and exterminating war, as a part of his religion, against all the rest of mankind. THE ESSENCE OF HIS DOCTRINE WAS VIOLENCE AND LUST : TO EXALT THE BRUTAL OVER THE SPIRITUAL PART OF HUMAN NATURE.
Between these two religions, thus contrasted in their characters, a war of twelve hundred years has already raged. That war is yet flagrant; nor can it cease but by the extinction of that imposture, which has been permitted by Providence to prolong the degeneracy of man. While the merciless and dissolute dogmas of the false prophet shall furnish motives to human action, there can never be peace upon earth, and good will towards men. The hand of Ishmael will be against every man, and every man's hand against him.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "In the seventh century of the Christian era, a wandering Arab of the lineage of Hagar, the Egyptian, combining the powers of transcendent genius, with the preternatural energy of a fanatic, and the fraudulent spirit of an impostor, proclaimed himself as a messenger from Heaven, and spread desolation and delusion over an extensive portion of the earth. Adopting from the sublime conception of the Mosaic law, the doctrine of one omnipotent God; he connected indissolubly with it, the audacious falsehood, that he was himself his prophet and apostle. Adopting from the new Revelation of Jesus, the faith and hope of immortal life, and of future retribution, he humbled it to the dust by adapting all the rewards and sanctions of his religion to the gratification of the sexual passion. He poisoned the sources of human felicity at the fountain, by degrading the condition of the female sex, and the allowance of polygamy; and he declared undistinguishing and exterminating war, as a part of his religion, against all the rest of mankind. THE ESSENCE OF HIS DOCTRINE WAS VIOLENCE AND LUST : TO EXALT THE BRUTAL OVER THE SPIRITUAL PART OF HUMAN NATURE.
Between these two religions, thus contrasted in their characters, a war of twelve hundred years has already raged. That war is yet flagrant; nor can it cease but by the extinction of that imposture, which has been permitted by Providence to prolong the degeneracy of man. While the merciless and dissolute dogmas of the false prophet shall furnish motives to human action, there can never be peace upon earth, and good will towards men. The hand of Ishmael will be against every man, and every man's hand against him." in the context of "Passage on Muhammad by an anonymous author in The American Annual Register for the Years 1827-8-9 (1830), edited by Joseph Blunt, Ch. X, p. 269. Robert Spencer attributed the authorship to Adams in The Politically Incorrect Guide to Islam (and the Crusades) (2005), p. 83, but provided no clear documentation as to why this attribution was made.
 • J. Q. Adams acknowledged authorship for his chapters in The American Annual Register in his diary, entry for April 9, 1830 https://www.masshist.org/publications/jqadiaries/index.php/document/jqadiaries-v36-1830-04-09-p414/dual." to mean that wisdom is timeless.