Is it permissible to make Dhikr (Remembrance of Allah) by uttering La ilaha illa Allah (there is no god but Allah) in addition to Muhammad is the Messenger of Allah? And what is the ruling on making Dhikr by these words on a regular basis?
Bearing witness to the Oneness of Allah, and to the Prophethood of Muhammad (peace be upon him) (Part No. 2; Page No. 534) is obligatory and without which one cannot be called a Muslim. Moreover, making Dhikr with La ilaha illa Allah only is greatly rewarded, because Shari`ah states so, and it is the best kind of Dhikr ever said by the Prophet (peace be upon him) and the prophets before him.However, taking Shahadah (Testimony of Faith) as Wird (portion of Qur'an recited with consistency) and repeating it on a regular basis has no evidence in the texts of the Qur'an or the Sunnah. All goodness is to be found in following what is authentically reported, restricting your Dhikr to it, and offering many blessings upon the Prophet (peace be upon him) at all times.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.