In addition to the Old Testament references, the prophetical discourses of our Lord uttered near the close of his ministry and recorded in the synoptical gospels will throw much light on the Book of Revelation. The omission of these from the gospel of John may be accounted for by the fact that in the Revelation the apostle had made such large use of them. The important prediction of Paul concerning the man of sin, found in 2 Thessalonians ii, must also be compared with those of John. 3. _The emblems and symbols of the Revelation must be interpreted by the light of the Jewish Scriptures and ritual._ This, indeed, follows as a corollary form the preceding rule, but is of so much importance as to deserve special mention. Sometimes a word or a figure of speech or the connections of a sentence or a passing allusion to some sacrificial service will afford a clew to what at the time was in the mind of the writer. Inasmuch as he was a Jew, “taught according to the perfect manner of the law of the fathers,” familiar with the Scriptures, traditions, usages, and history of his religion, his interpretation of symbols and emblems would naturally be such as would occur to the mind of a Jew. We must place ourselves as near as possible to his standpoint. Yet, as he was also an inspired apostle of the Lord Jesus Christ, we must be prepared to concede that he read deeper into these mysteries than his fellows did and was able to import into them a richer meaning. 4. _Particular attention must be given to the numbers found in the book._ Much that is fanciful and extravagant has, it must be conceded, been written on this subject, and to many persons any discussion of it is distasteful. Yet it is certain, as the Wisdom of Solomon says, that God has “ordered all things in measure and number and weight.” Otherwise there could be no such thing as exact science. Truths lie veiled in figures, for these represent fixed principles and plans in the divine mind. As a general truth, it may be stated that the ideas expressed by numbers, not only in this book, but throughout the Bible, whenever these are used symbolically, are those of fullness, exactness, and perfection, on one hand, or deficiency, incompleteness, and imperfection, on the other. The numbers which figure most largely in symbolism are seven, twelve, six, and three and a half. Seven is called the sacred number, and seems to express the idea of perfection or fullness to the highest degree and in the most unlimited sense. As seven days make a complete week, whole and entire, without redundancy or deficiency, so that to which the number seven is attached must be taken as perfect, fully developed, as a complete whole. The expressions “seven spirits,” “seven seals,” “seven trumpets,” etc., imply that what they represent must be taken as entire, with no possible capacities lying in them unexhausted.