From Bernard Lewis, The Middle East (1995), p223:
"Towards the end of the eighteenth century a Muslim visitor to England, Mirza Abu Talib - one of the first to have left a written account of his impressions - described a visit to the House of Commons, and his astonishment when it was explained to him that its functions and duties included the promulgation of laws and the fixing of penalties for wrongdoers. Unlike the Muslims, he explained to his readers, the English have not accepted a divine law revealed from heaven, and were therefore reduced to the expedient of making their own laws "in accordance with the necessities of time and circumstance, the state of affairs, and the experience of judges"."
Additional note (19 November 2011)
I have now tracked down what appears to be Lewis's source. I consulted it in a translation entitled Travels of Mirza Abu Taleb Khan in Asia, Africa, and Europe, during the years 1799, 1800, 1801, 1802, and 1803, published in London in 1810. It doesn't quite tally with Lewis's paraphrase, though this may be the fault of the translation. This is what it says:
"Some of [MPs'] duties have been before described: but when their attention is not taken up with great political subjects, they employ themselves in considering the internal regulations, and plans for improving the state of the country, and, in fact, take cognizance of every thing that is going forward. Even the laws respecting culprits are abrogated or altered by Parliament; for the Christians, contrary to the systems of the Jews and Mohammedans, do not acknowledge to have received any laws respecting temporal matters from Heaven, but take upon themselves to make such regulations as the exigencies of the times require."
These passages are also of interest:
"Liberty may be considered as the idol, or tutelary deity, of the English; and I think the common people here enjoy more freedom and equality than in any other well-regulated government in the world. No Englishman, unless guilty of a breach of the laws, can be seized, or punished, at the caprice or from the gust of passion of the magistrate: he may sometimes be confined on suspicion, but his life cannot be affected, except on positive proof."
"In their newspapers and daily publications, the common people often take the liberty of abusing their superiors."
"The British Constitution is of the mixed form, that is, an union of the monarchical, aristocratical, and democratical governments, represented by the King, Lords, and Commons; in which the powers of each are so happily blended, that it is impossible for human wisdom to produce any other system containing so many excellences, and so free from imperfection."
"It is requisite to explain, to Mohammedans, that, in England, Law and Religion are distinct branches, and that the duty of a clergyman is limited to watching over the moral and spiritual conduct of his flock, to burying the dead, visiting the dying, uniting persons in marriage, and christening children...."