By class, in this case, I mean category.
Christ offered no commentary on how to rearrange society — to rearrange categories or classes or groups — to achieve some improvement in temporal, worldly conditions.
Christ MENTIONS things of worldly interest, but his topic is NEVER temporal, worldly, civic, social, political, economic, etc. affairs.
Everything he says concerns your soul.
Jesus is God. He is in total agreement with EVERYTHING the FATHER says. So if God says "I am the Lord your God who teaches you to profit" (Isa 48:17) then we know that Jesus also says that.
So, you can't limit yourself to just the four gospels. What Jesus says there is just a small portion of what He has told us in His word.
And in the Word He speaks a lot about this world. In fact (IIRC) He talks about money more than He talks about sin.
Salvation is easy. Living here wisely is very difficult, and so He talks about that the most.