How was the intention during the time of the Prophet, may Allah bless him and grant him peace, and what is its simple definition?

Linguistically and technically, niyyah (intention) is al-qaṣd (purpose/aim). One who examines the Arabs' usage of this word will find that its various forms revolve around al-qaṣd. It has been inclined that the Shariah did not alter the meaning of niyyah from its Arabic usage. In short, niyyah is al-qaṣd, and the meaning of al-qaṣd is clear and needs no further elaboration. Actions are dependent on the agent's purpose and intention.