فَإِنْ لَمْ يَنْوِ حَتَّى أَصْبَحَ:
Translation: If he had not made the intention by morning.
“If he has not intended until morning” describes omission of a formal intention during the night. Quduri allows a later intention for this fixed-time class within the stated deadline.
The permission presupposes that nothing invalidating the fast has been done after true dawn. The precise end of the window needs care, as the source phrase and later Hanafi clarification are not identical.