40 days

[Fti]

Is there anywhere in Islam that talks about 40 days seclusion from the world or just about 40 days for doing something in order to make it habit?

[Flos]

Salam,

I found this as an answer: https://blog.tarteel.ai/habit-of-prayer/

Habit of Prayer There is a spiritual aspect to building habits. Our metaphysical state changes, and so does our physiological state shift at the interchange of habits....

[Murid]

:salam:
:bism:
It depends what are your definitions of Islam.

There were similar practices done before. For example a rock split and water spring originated at that place after itiqaf for 40 days of intense prayers.
It is common in many examples.
We should not perceive it as must, but it is maybe prescribed such that the disciple has zeal and consistecy.

There are also practices (you've probably seen the pit in the batman movie) that they put you in similar cell in chisti tariqah and test you for chilla time. That is intense.
Some even do a lot longer "chillas", are unorthodox etc.