In making the Luwaran the Mindanao judges selected such laws as in their judgment suited the conditions and the requirements of order in Mindanao. They used the Arabic text as a basis, but constructed their articles in a concrete form, embodying genuine examples and incidents of common occurrence in Mindanao. In some places they modified the sense of the Arabic so much as to make it agree with the prevailing customs of their country. In a few instances they made new articles which do not exist in Arabic but which conform to the national customs and common practices. The authority of the Luwaran is universally accepted in Mindanao and is held sacred next to that of the Quran. The Mindanao judge is at liberty to use either of them as his authority for the sentence to be rendered, but as a rule a quotation from the Quran bearing on the subject is desirable. All datus and viziers and all persons acting in the capacity of a chief or a vizier find the Luwaran very convenient and helpful. Very few people can become kali, but all who are able to read can study and use the Luwaran. Consequently the Luwaran has had general use, and copies of it are seen in all the districts that speak the Magindanao dialect. To establish this fact copies of it were secured from the ruling datus of Bagumbayan and of Saraya or the upper valley. The copy [12] secured from Datu Mastura is by far the most complete of all. The text is well written, neat, and distinct. The original Arabic articles are written separately on the margin of the book and opposite the Magindanao articles with which they were supposed to correspond. Datu Mastura is the best living descendant and representative of the house of Mindanao, and he probably owns the most reliable books and documents that have been transmitted from the previous generations. This book is certainly the best specimen of Magindanao literature; it is genuine, correct, and well written. On account of inability to secure the book itself, an accurate and exact copy of the same was taken. The Magindanao articles are written separately and are numbered for convenience in reference. The translation is not exactly literal, but nearly so. The Arabic marginal quotations are copied separately and are numbered in the order in which they appeared in the original copy. They are also translated, and a table indicating the Arabic quotation which corresponds to each article of the Luwaran is attached to the introduction to the translation. In actual practice the Moros do not distinguish between custom and law. Many of their customs are given the force of law, and many laws are set aside on account of contradiction to the prevailing customs of the day. Slavery is such an established custom and institution of the land that it is generally sanctioned and supported in the Luwaran.