Is it permissible to perform Dhikr with "Hasbi Allah wa Ni'ma Al-Wakeel" (Allah is sufficient for me, and [He is] the best Disposer of affairs) and to seek forgiveness with the wording "Astaghfirullah Al-Atheem min kulli thanb Al-Atheem" (I seek forgiveness from Allah, the Most Great, for every great sin)?

It is permissible to perform dhikr (remembrance of God) with "Hasbiyallahu wa Ni'mal Wakeel" (Allah is sufficient for us, and [He is] the best Disposer of affairs), as it is mentioned in the Holy Quran and Sahih Al-Bukhari. Its meaning is "He is sufficient for me."

As for seeking forgiveness with the formula "Astaghfirullah Al-Azeem" (I seek forgiveness from Allah, the Magnificent), it is correct. However, adding "min kulli dhanbin azeem" (from every great sin) has no origin from the Prophet, peace and blessings be upon him, and it contradicts the authentic hadiths that call for seeking forgiveness from all sins, minor and major.