This passage contains the striking addition of the parenthetical explanation ἦσαν γὰρ ἁλεεῖς. That this should occur in a narrative portion, and not in a saying of Jesus, is the more significant. For the rest, the saying ascribed to Jesus runs word for word (tho its brevity in this case robs this fact of any very remarkable significance); in the narrative portion Matthew mentions that Simon was called Peter (a remark which Mark saves till he comes to the formal naming of the twelve), and in the conclusion he says "they left the boat and their father," while Mark says "they left their father in the boat," adding, "with the hired men." Mark says Jesus _called_ the two "immediately." Matthew says they _left_ "immediately." CHAPTER VI USE OF A COMMON DOCUMENT BY MATTHEW AND LUKE The document used by Matthew and Luke as the source of their common non-Marcan material was for some time generally identified with the "Logia" which Papias says Matthew, the disciple of the Lord, wrote in Hebrew, undoubtedly meaning Aramaic. Until some sufficient justification for this identification has been given, it seems better to refer to the common non-Marcan source of Matthew and Luke under the more colorless symbol Q. The common non-Marcan tradition of Matthew and Luke consists almost exclusively of logian material. It contains a few parables, brief, and dealing usually with the "kingdom of heaven," and one or two sections (such as that concerning the centurion from Capernaum, and the Temptation) which may quite properly be regarded as narrative, but which also contain large logian content and may have been introduced for the sake of the sayings. The proof that the source of the common non-Marcan material of Matthew and Luke was a document and not an oral tradition lies in the extent and character of the agreements between the two Gospels; it cannot be summarized in a paragraph, but comes out only in a detailed examination of the double tradition such as is undertaken in the following pages. Before the theory of a common documentary source for the non-Marcan material in Matthew and Luke can be accepted, it must defend itself against two apparently simpler hypotheses, viz., that Matthew copied from Luke or Luke from Matthew.