Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
quran:93:1In the name of Allah, the Entirely Merciful, the Especially Merciful.

By the morning brightness  

By the forenoon, that is to say, the first part of the day or all of it,
القرآن:٩٣:١بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ

وَالضُّحَىٰ  

{والضحى} أي أول النهار أو كله.