Mirza showered his praises to his sincere sahabi Mir Abbass in the following words:
"That Eternal Being who had given you this sincerity, is the One who had chosen you Himself." (Letter dated 21st May 1883, Maktoobaat-e-Ahmadiyya Vol.1)
"AlHamdolillah that God had made you the closest of my ANSARS (helpers). This humble self takes pride in your existence and I consider you a complete embodiment of mercy from God." (Letter dated 29th October 1883, Maktoobaat-e-Ahmadiyya Vol.1)
Here is the climax:
He received following Wahi from Allah:
"Mir Sahib is a person with great spiritual condition and has a spiritual connection with this humble self. And to prove his level of sincerity, it is enough that once this humble self received an inspiration in his favour: 'aslohoo sabitun wa farohoo fis samaa' (his roots are firmly fixed and his branches are in the sky)." (Izala-e-Auham, Roohani Khazain vol.3 p.528)
After this wahi and after several years close association with Mirza, Mir Abbass sent lanat to mirza and reverted to Islam.
Does Allah makes a mistake? Does he send wrong wahi? Does not all knowing present, past future? Does he not know what is in our hearts?
OFCOURSE ALLA IS ALL KNOWING.
Mirza was a liar. The evidence is overwhelming. O mirzais, please think about it. If you are Allahs servent, then accept Allahs will. If you are Mirza's servents, then we have done our job and given you the proofs.
I thank Dr. Syed Rashid Ali for above work. Here is the link for further reading.