Mirza Ghulam Ahmad lusted after his niece Muhammadi Begum for his entire life. Initially, he was giving guarantees that he would end up marrying this innocent girl. Read other essay’s on this topic here: https://ahmadiyyafactcheckblog.com/?s=Muhammadi
Summary of these scans
In his book Malfoozat Mirza Qadiani defines categories of TAQDIR (fate) as
“two main types of TAQDIR.
1.TAQDIR E MUALLAQ:- is the fate that is hanging and can be avoided with prayers and SADAQAT (charity).
2.TAQDIR E MUBRAM the fate that is inevitable. It is further divided into two types i.e.:-
(a) GHAIR HAQIQI (Inevitable but unreal) can be avoided or deferred with prayers and Sadaqat.
(b) Taqdir e Mubram Haqiqi . It is so firm and unavoidable that even the collective prayers of 100 prophets can not avoid this.
Now in hIs book Majmua e Ishtiharat Volume 2 page 43, Mirza Ghulam Qadiani writes that happening of Mirza’s Nikah with Muhammadi Begum is the kind of TAQDIR E MUBRAM that can not be avoided (meaning Taqdir e Mubram Haqiqi), because otherwise the words of God would become false. So if she is not married to him, he would be called as a liar in that case.