save git hash in the same file without changing the current hash code

Question

I am trying to code up a version control schema based library system. So as a part of the functionality i am trying record the current hash of a file and insert it as a part of the history and save it but not to change the current version!!!! because when i save the file , the hash code immediately changes which is not what i wanted Pls help me in this !!! Thanks in advance I tried the git rev-parse HEAD 1.txt but still the problem persists !!!! Attaching the screenshot for your perusal

Here in the screenshot when git hash-object 1.txt i am getting "79f3721a53ea877e2cc89e6655f1922ed8f01e23" but in the file above the old hash code has got piped !!!!

Pls help on this !!!!!!!