Ittaqū is interpreted in five ways:
1. Ittaqū [practice ittiqāʾ], is used in the sense of feeling awe; as in the following verses:
O mankind, have ittiqāʾ of your Lord (that is, feel awe before your Lord)! (al-Nisāʾ 4:1)
O mankind, have ittiqāʾ of your Lord (that is, feel awe before your Lord); indeed, the convulsion of the Hour is a terrible thing. (al-Ḥajj 22:1)
When their brother Hūd said to them, "Will you not have ittiqāʾ?" (that is, will you not feel awe before Allah?) (al-Shuʿarāʾ 26:124)
(Nūḥ said to his people): "Will you not have ittiqāʾ?" (that is, will you not feel awe before Allah?) (al-Shuʿarāʾ 26:106)
(Ṣāliḥ said to his people): "Will you not have ittiqāʾ?" (that is, will you not feel awe before Allah?) (al-Shuʿarāʾ 26:142)
(Lūṭ said to his people): "Will you not have ittiqāʾ?" (that is, will you not feel awe before Allah?) (al-Shuʿarāʾ 26:161)
(Shuʿayb said to his people): "Will you not have ittiqāʾ?" (that is, will you not feel awe before Allah?) (al-Shuʿarāʾ 26:177)
And [We sent] Abraham (as a messenger). When he said to his people: "Worship Allah and have ittiqāʾ of Him" (that is, feel awe before Him)! (al-ʿAnkabūt 29:16)
2. Ittaqū is used in the sense of worship; as in the following verses:
Warn that there is no deity except Me. So have ittiqāʾ of Me (that is, worship Me)! (al-Naḥl 16:2)
So do you have ittiqāʾ for other than Allah (that is, do you worship other than Allah / will you still not worship Allah)? (al-Naḥl 16:52)
You have no deity other than Him. So will you not have ittiqāʾ (that is, will you not worship)? (al-Muʾminūn 23:23)
I am your Lord; so have ittiqāʾ of Me (that is, worship)! (al-Muʾminūn 23:52)
Go to the people of Pharaoh. Will they not have ittiqāʾ (that is, will they not worship)? (al-Shuʿarāʾ 26:11)
3. The phrase ittaqullāha [practice ittiqāʾ toward Allah] is used in the sense of "do not disobey Allah"; as in the following verse:
Enter houses from their doors and have ittiqāʾ of Allah (that is, do not disobey Him regarding what He has commanded you)! (al-Baqara 2:189)
4. al-Taqwā is used in the sense of tawhid (the oneness of God); as in the following verses:
We enjoined you to have ittiqāʾ of Allah (that is, to affirm the oneness of Allah). But if you disbelieve, then indeed, to Allah belongs whatever is in the heavens and whatever is on the earth. (al-Nisāʾ 4:131)
Allah has tested their hearts for taqwā (that is, for tawhid). (al-Ḥujurāt 49:3)
5. al-Taqwā is used in the sense of ikhlas (sincerity); as in the following verse:
Indeed, that is from the taqwā of hearts (that is, from the ikhlas of hearts). (al-Ḥajj 22:32)