All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The maxim that reads: “the change of rules should not be denied due to time change” is mentioned in the Hanafi book “Durar Al-Hukkaam”, by ‘Ali Haydar who said after mentioning this maxim: “The rulings that may change as times change are the rulings that are based on customary practices and habits because as time changes the needs of people change.”
So, we advise you to refer to that book for more details on this maxim, and you may also refer to the book of “I’laam Al-Muwaqqi’een” by Ibn Al-Qayyim as he mentioned this maxim and explained it very well.
Allaah Knows best.