It was narrated from Ibn 'Umar that he used to say: "None should fast except the one who intended to fast before dawn".
The Prophet Muhammad ﷺ taught us that intentions are very important in Islam, as they can help guide our decisions and actions towards what is right and beneficial for ourselves and others around us. He also taught us that it is important to be mindful of our intentions when performing any action or deed, as this will ensure that whatever we do has meaning behind it rather than just being done out of habit or routine.