Does the meaning of the word "Ashhad" (I bear witness) entail affirmation by the heart and utterance by the tongue, and is this what is intended in "Ashhadu an la ilaha illa Allah" (I bear witness that there is no god but Allah)?

The testimony that there is no god but Allah does not benefit its holder merely by knowledge and declaration. Rather, it must be accompanied by a conviction of the heart that includes commitment, affirmation, and submission. Just as the hypocrites and Jews knew the truth of the Prophet's prophethood, peace and blessings be upon him, but they did not believe due to their lack of commitment and submission. Similarly, Abu Talib knew about the prophethood of Muhammad, peace and blessings be upon him, but he did not believe because his knowledge was not coupled with love and submission. Thus, the meaning of "I bear witness" is affirmation and acknowledgment with the tongue, conviction in the heart, and submission and commitment.