This is the reply below that I received in FB. So now I can also type صبحها :)
You are looking for the character "ZWNJ" -- Zero-With Non-Joiner. On an android keyboard it's sometimes labeled simply "zwnj". On a Windows computer with the keyboard set to Persian, you can press Ctrl+Shift+2 to add a ZWNJ character. صبحها. :D
It seems to be Shift+space on a mac. On Linux, you should enable the "compose" feature of the keyboard, and then "compose"+space+space.