What is the main topic of Riyad us Saliheen Hadith 1134?

Riyad us Saliheen Hadith 1134 is from chapter "The Book of Virtues". Summary: The Prophet (ﷺ) said, "Perform Witr prayer before dawn." [Muslim].

Riyad us Saliheen: Hadith 1134

9. The Book of Virtues

1134

Riyad us Saliheen

وعن أبي سعيد الخدري رضي الله عنه أن النبي صلى الله عليه وسلم قال‏:‏ ‏‏أوتروا قبل أن تصبحوا‏"‏‏‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏‏

Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:

The Prophet (ﷺ) said, "Perform Witr prayer before dawn."

[Muslim].

Reference: Sunnah.com : Book 9, Hadith 145
Arabic/English book : Book 9, Hadith 1135