question #1 Sahih al-Bukhari 579, Book 9, Hadith 55 : What is the significance of completing at least one rak`a of a prayer within its designated time?

Allah’s Messenger (ﷺ) said, “Whoever could get one rak`a (of the Fajr prayer) before sunrise, he has got the
(morning) prayer and whoever could get one rak`a of the `Asr prayer before sunset, he has got the
(`Asr) prayer.”