They do not appreciate Allah as He should be appreciated (and no true concept of His attribute they have formed to pay Him the respect He deserves). Surely, Allah is All-Powerful, All-Mighty
They did not justly appraise (the manifestations of the qualities denoted by the Name) Allah... Indeed, Allah is the Qawwi and the Aziz (One who is powerful and whose use of His power is unchallengeable).
Sayyed Abbas Sadr-Ameli
They have not estimated Allah with the estimation that is due to Him. Verily Allah is Strong, Mighty
Al-muntakhab fi tafsir al-Qur'an al-Karim
They -the Meccan infidels- did not credit Allah with the attributes asserted as His own. Indeed, Allah is Qawiyun (Omnipotent) and Azizun, The Almighty Who prevails against the whole and all in all