Have an intention to fast before dawn.

This hadith emphasizes the importance of having an intention when fasting. It was narrated from Hafsah that there is no fast for one who does not intend to fast before dawn. This means that a person must have the intention to fast in their heart before they start their day, otherwise, their fasting will not be accepted by Allah. This hadith teaches us that we should always strive to have good intentions and be mindful of our actions throughout the day so that we can reap its rewards in this life and in the hereafter.