Is the individual obligation of al-Hisbah waived for the physically weak and the disabled? And is the duty of munkar (enjoining good and forbidding evil) waived for the disabled when backbiting occurs in a gathering?

Hisbah (accountability), calling to Allah, enjoining good, and forbidding evil verbally are collective obligations (fard kifaya) that do not cease due to physical weakness. They include the disabled and others, according to their capacity. So, whoever sees an evil and is unable to change it with his hand, let him change it with his tongue. This applies to everyone who is capable. Enjoining good and forbidding evil may become an individual obligation (fard ayn) if the person is the only one capable of removing it. Denouncing evil in one's heart is not sufficient for someone who is able to denounce it verbally. Many scholars were disabled or physically weak, yet they fulfilled the duty of enjoining good and forbidding evil.