matthew 5:1 And seeing the multitudes, he went up into a mountain: and when he was set, his disciples came unto him: - Free Bible Online

      That this is the same Discourse as that in Lu 6:17-49 --only reported more fully by Matthew, and less fully, as well as with considerable variation, by Luke--is the opinion of many very able critics (of the Greek commentators; of CALVIN, GROTIUS, MALDONATUS--Who stands almost alone among Romish commentators; and of most moderns, as THOLUCK, MEYER, DE WETTE, TISCHENDORF, STIER, WIESELER, ROBINSON). The prevailing opinion of these critics is that Luke's is the original form of the discourse, to which Matthew has added a number of sayings, uttered on other occasions, in order to give at one view the great outlines of our Lord's ethical teaching. But that they are two distinct discourses--the one delivered about the close of His first missionary tour, and the other after a second such tour and the solemn choice of the Twelve--is the judgment of others who have given much attention to such matters (of most Romish commentators, including ERASMUS; and among the moderns, of LANGE, GRESWELL, BIRKS, WEBSTER and WILKINSON. The question is left undecided by ALFORD). AUGUSTINE'S opinion--that they were both delivered on one occasion, Matthew's on the mountain, and to the disciples; Luke's in the plain, and to the promiscuous multitude--is so clumsy and artificial as hardly to deserve notice. To us the weight of argument appears to lie with those who think them two separate discourses. It seems hard to conceive that Matthew should have put this discourse before his own calling, if it was not uttered till long after, and was spoken in his own hearing as one of the newly chosen Twelve. Add to this, that Matthew introduces his discourse amidst very definite markings of time, which fix it to our Lord's first preaching tour; while that of Luke, which is expressly said to have been delivered immediately after the choice of the Twelve, could not have been spoken till long after the time noted by Matthew. It is hard, too, to see how either discourse can well be regarded as the expansion or contraction of the other. And as it is beyond dispute that our Lord repeated some of His weightier sayings in different forms, and with varied applications, it ought not to surprise us that, after the lapse of perhaps a year--when, having spent a whole night on the hill in prayer to God, and set the Twelve apart, He found Himself surrounded by crowds of people, few of whom probably had heard the Sermon on the Mount, and fewer still remembered much of it--He should go over its principal points again, with just as much sameness as to show their enduring gravity, but at the same time with that difference which shows His exhaustless fertility as the great Prophet of the Church.

JFB.