(Luke 6:20-42)
The Sermon on the Mount is the name usually given to a discourse delivered by Jesus to his disciples and a multitude on a mountain near Capernaum. Sometimes the version of the sermon given in Luke is referred to as the "Sermon on the Plain" because it is shorter than the one written about in the Gospel of Matthew.

Basically, the sermon is a contrast between two kinds of men. The first group are those who by all outward appearance are to be pitied, but in the judgment of Jesus are blessed or happy because of what is promised to them. They are poor and needy, hungry and sad. Jesus speaks not of their literal condition, but spiritually--they feel dissatisfied with this present world and long for what God has to give them.

The other group of men are those who have what the present can offer--satisfaction of their desires for material goods, happiness and a good reputation among men. These men do not want anything more. They feel no need to cry out to God in prayer, for they think they have enough. The time will come, says Jesus, when they will have nothing.
(Merrill F. Unger, Unger's Bible Dictionary, Moody Press, Chicago, Illinois, 1974, 179, 997.) (D. Guthrie and J. A. Motyer eds. The New Bible Commentary: Revised. Wm. B. Eerdmans Publishing Co., Grand Rapids, Michigan, 1970, 898, 899.)