xterm – select font name and size from command line and set it as default

I have been very busy last week and specially yesterday with 20 hours of continueous work, but managed to get this working :).

When you right click on Xterm with Ctrl pressed, there pops up a menu for selecting the size of the font. I have always wondered how to set this as default font and/or use this from the command line. So I searched my old homedir and looked for few of the docs that I had to get the information. Here is what I found.