151 Moreover, Matthew proceeds thus: “But pray ye that your flight be not in the winter, neither on the Sabbath day.” Part of this is given and part omitted by Mark, when he says, “And pray ye that your flight be not in the winter.” Luke, on the other hand, leaves this out entirely, and instead of it introduces something which is peculiar to himself, and by which he appears to me to have cast light upon this very clause which has been set before us somewhat obscurely by these others.
For his version runs thus: “And take heed to yourselves, lest at any time your hearts be overcharged with surfeiting, and drunkenness, and cares of this life, and so that day come upon you unawares. For as a snare shall it come on all them that dwell on the face of the whole earth. Watch ye therefore, and pray always, that you may be accounted worthy to escape all these things that shall come to pass.” This is to be understood to be the same flight as is mentioned by Matthew, which should not be taken in the winter or on the Sabbath day.
That “winter,” moreover, refers to these “cares of this life” which Luke has specified directly; and the “Sabbath-day” refers in like manner to the “surfeiting and drunkenness.” For sad cares are like a winter; and surfeiting and drunkenness drown and bury the heart in carnal delights and luxury— an evil which is expressed under the term “Sabbath-day,” because of old, as is the case with them still, the Jews had the very pernicious custom of revelling in pleasure on that day, when they were ignorant of the spiritual Sabbath.
Or, if something else is intended by the words which thus appear in Matthew and Mark, Luke's terms may also be taken to bear on something else, while no question implying any antagonism between them need be raised for all that. At present, however, we have not undertaken the task of expounding the Gospels, but only that of defending them against groundless charges of falsehood and deceit. Furthermore, other matters which Matthew has inserted in this discourse, and which are common to him and Mark, present no difficulty.
On the other hand, with respect to those sections which are common to him and Luke, [it is to be remarked that] these are not introduced into the present discourse by Luke, although in regard to the order of narration here they are at one. But he records sentences of like tenor in other connections, either reproducing them as they suggested themselves to his memory, and thus bringing them in by anticipation so as to relate at an earlier point words which, as spoken by the Lord, belong really to a later; or else, giving us to understand that they were uttered twice over by the Lord, once on the occasion referred to by Matthew, and on a second occasion, with which Luke himself deals.
Source: The Harmony of the Gospels (New Advent)