The conditions of Shahadah (Bearing witness that there is no god but Allah) that must be fulfilled by the one who pronounces it

 They are seven:

First: to know its meaning (what it affirms and negates).

Second: To have absolute Faith in it at heart.

Third: To believe in it publicly and secretly.

Fourth: To accept it and not to reject any of its necessities or requirements.

Fifth: To purify one's intention in its regard.

Sixth: To believe in it from one's deepest heart and not only by tongue.

Seventh: To have passion for it and for its adherents and to take friends and enemies only according to its very criteria.

The textual proof of making knowledge of the meaning of the Shahadah a condition for pronouncing it

Allah the Almighty says: {Except for those who bear witness to the truth knowingly} i.e. believe in the Oneness of Allah, {and they know}. (Az-Zukhruf, 86) i.e. they know in their heart the facts about the Oneness of Allah and its meaning.

Prophet Muhammad (Peace be upon him) says: "He who died knowing (fully well) that there is no god but Allah entered Paradise ". (Sahih Muslim)