The Relation of the Shahaadah with the Types of Tawheed
Question 5: But does the Shahaadah Comprise the Types of Tawheed?
The Answer: Indeed it does encompass the types of Tawheed altogether, either by way of inclusion or implication. This is because a persons statement, “I testify that La ilaaha illallaah,” is immediately understood such that the intended meaning is Tawheed al-’Ibaadah (i.e. to single Allaah out with all worship). This type of Tawheed, also called Tawheed al- Uloohiyyah, is inclusive of Tawheed ar-Ruboobiyyah (i.e. to single Allaah out with Creation, Sovereignty and Control of affairs), because everyone who worships Allaah alone, would not worship Him until he firmly attests that ar-Ruboobiyyh is exclusively His.
It also comprises the Tawheed of al-Asmaa’was-Sifaat, because man does not worship except what he knows to be worthy of worship due to the Names and Attributes He has. This is why Ibraaheem said to his father:
O my father! Why do you worship that which hears not, sees not and cannot avail you in anything? [Qur’aan, soorat Maryam (19): 42].
So, the Tawheed of al-’Ibaadah, which is Tawheed al- Uloohiyyah, comprises both Tawheed ar-Ruboobiyyah and that of al-Asmaa’ was-Sifaat.
 Tawheed al-Asmaa’ was-Sifaat is to single Allaah out with all of the most beautiful Names and superlative Attributes which He has affirmed for Himself or which His Messenger, Muhammad صلى الله عليه و سلم has affirmed for Him, without Tahreef (changing or distorting the meaning of the Names and Attributes), without Ta’teel (denying or suspending their meanings), without Takyeef (specifying how they are), and without Tamtheel (exemplification). It also involves denying all that which Allaah has denied from Himself.
Translated by Dr Saleh as Saleh rahimahullaah
Source : Understanding Worship – Fiqh ul-‘Ibadah – Shaykh ibn Uthaymeen