NOTE 37. This comparison is not intended to be understood in its literal sense, for the smallest of the tribe of 'Ád is said to have been sixty cubits high: the largest, a hundred! The tribe of 'Ád were a race of ancient Arabs, who, according to the Ḳur-án and Arab historians, were destroyed by a suffocating wind, for their infidelity, after their rejection of the admonitions of the prophet Hood. NOTE 38. The Arabs generally calculate distances by time. The average distance of a day's journey is from twenty to twenty-five miles; the former being the usual rate of caravan-travelling. NOTE 39.--_On the Privacy of Arab Dwellings._ In a palace, or large house, there is generally a wide bench of stone, or a wooden couch, within the outer door, for the accommodation of the door-keeper and other servants. The entrance-passage leads to an open court, and, for the sake of preventing persons at the entrance, or a little within it, from seeing into the court, it usually has two turnings. We may, therefore, understand the motive of the King in seating himself in the place here described to have been a desire that he might not, if discovered, be supposed to be prying impertinently into the interior of the palace. Respect for the privacy of another's house is a point that is deemed of so much importance that it is insisted upon in the Ḳur-án, in these words:--"O ye who have become believers, enter not any houses, besides your own houses, until ye shall have asked leave, and saluted their inhabitants; this will be better for you: peradventure ye will be admonished. And if ye find not in them any person, enter them not, until leave be granted you; and if it be said unto you, Return, then do ye return; this will be more decent for you; and God knoweth what ye do. But it shall be no crime in you that ye enter uninhabited houses wherein ye may find a convenience."[170] When a visiter finds the door open, and no servant below, he usually claps his hands as a signal for some person to come to him; striking the palm of his left hand with the fingers of the right: and even when leave has been granted him to enter, it is customary for him, when he has to ascend to an upper apartment, to repeat several times some ejaculation, such as "Permission!" or, "O Protector!" (that is, "O protecting God!"), as he goes up, in order that any female of the family, who may chance to be in the way, may have notice of his approach, and either retire or veil herself. Sometimes the servant who precedes him does this in his stead. NOTE 40. These verses are translated from the Calcutta edition of the first two hundred nights, as more apposite than those which are inserted in their place in the edition of Cairo.