Maliks Muwatta Book 001, Hadith Number 020.

Section : Duluk ash-Shams and Ghasaq al-Layl.

Yahya related to me from Malik that Da'ud ibn al-Husayn said that someone had told him Abdullah ibn Abbas used to say, "Duluk ash-shams begins from when the sun passes the meridian. Ghasaq al-layl is the gathering of the night and its darkness."