James Tissot The Sermon of the Beatitudes (1886-1896)
This is the closest I found where (even though it is not truly on a plain) Jesus is looking up at his disciples
Gustave Dore, Jesus Prechant Sur La Montagne (1865)
For broader context it is also followed by the Parable of the Mote and the Beam
Domineco Fetti, The Parable of the Mote and Beam (1619)
And a couple images that reflect the All Saints nature of the day
The Forerunners of Christ with Saints and Martyrs (around 1423) en: Fra Angelico
Greek Icon of the Second Coming (around 1700)
Sign of the Rose 