Tafsir of Al-Inshiqaq 84:16

Swearing by the Various Stages of Man's Journey Allah swears,

فﻼ أقسم بالشفق

But no! I swear by Ash-Shafaq; It has been reported from Ali, Ibn Abbas, Ubadah bin As-Samit, Abu Hurayrah, Shaddad bin Aws, Ibn Umar, Muhammad bin Ali bin Al-Husayn, Makhul, Bakr bin Abdullah Al-Muzani, Bukayr bin Al-Ashaj, Malik, Ibn Abi Dhi'b, and Abdul Aziz bin Abi Salamah Al-Majishun, they all said, "Ash-Shafaq is the redness (in the sky). Abdur-Razzaq recorded from Abu Hurayrah that he said, "Ash-Shafaq is the whiteness.'' So Ash-Shafaq is the redness of the horizon, either before sunset, as Mujahid said or after sunset, as is well known with the scholars of the Arabic Language. Al-Khalil bin Ahmad said, "Ash-Shafaq is the redness that appears from the setting of sun until the time of the last `Isha' (when it is completely dark). When that redness goes away, it is said, Ash-Shafaq has disappeared.''' Al-Jawhari said, "Ash-Shafaq is the remaining light of the sun and its redness at the beginning of the night until it is close to actual nighttime (darkness).'' Ikrimah made a similar statement when he said, "Ash-Shafaq is that what is between Al-Maghrib and Al-Isha'.'' In the Sahih of Muslim, it is recorded from Abdullah bin Amr that the Messenger of Allah said,

وقت المغرب ما لم يغب الشفق

the time of Al-Maghrib is as long as Ash-Shafaq has not disappeared.'' In all of this, there is a proof that Ash-Shafaq is as Al-Jawhari and Al-Khalil have said

والليل وما وسق