Is it permissible to perform i'tikaf in the mosque every Thursday to recite the Quran, study religious knowledge, and pray Qiyam al-Layl in congregation, as was done in Ramadan, or is this considered an innovation (bid'ah)?

Devoting a specific act of worship to a particular time without

religious proof is considered an innovation (bid'ah). This includes singling

out a certain day for i'tikaf (spiritual retreat) and gathering for it.

While i'tikaf is an act of worship, singling it out for a specific time in

this manner is an added innovation that should be avoided. This is because

any act that the Prophet, peace and blessings be upon him, did not perform,

despite the reason for it being present and no impediment preventing it, is

considered an innovation. Indeed, it has been forbidden to single out Friday

night for prayer and its day for fasting.