What is the ruling of Islamic law on holding or attending vigils and celebrations such as the "Thursday gathering," the fortieth-day commemoration, and the annual commemoration for the soul of the deceased, and what is the correct legal stance on these practices?

Erecting marquees for reciting the Qur'an for the soul of the deceased, and what is known as the "Thursday," "Fortieth," or "Annual" commemorations, are reprehensible innovations (bid'ah) that were not reported from the Prophet (peace be upon him) nor from his companions. These practices are often accompanied by other reprehensible acts such as smoking, showing off, and extravagance. The Prophet (peace be upon him) said: "Whoever introduces into this matter of ours that which is not from it, it is rejected." It is obligatory to beware of innovations and to adhere to the Sunnah, for the Prophet (peace be upon him) said: "Indeed, whoever lives among you will see much disagreement. So, hold fast to my Sunnah and the Sunnah of the rightly guided Caliphs. Hold on to them with your molar teeth. And beware of newly invented matters, for every newly invented matter is an innovation, and every innovation is misguidance." It is not permissible to attend these innovative gatherings except for the purpose of denunciation. These matters should be explained to relatives gently and patiently, and they should be invited to the Sunnah, for these things benefit neither the deceased nor the living. Rather, they are inherited customs that are not approved by sacred law or by reason.