Allah (swt) is swearing by the dawn.
الْفَجْرِ (dawn): In Arabic means a wide split. The dawn is well known that it is the earliest time when the light tears through the darkness of the night. As if the day light is hidden in the darkness of night then comes the dawn that tears it up completely. Accordingly, the man who gets out of Allah’s (swt) instruction is called the (Al-Fajir) (the sinner) in Arabic, which is derived from this word (Al-Fajr) (the dawn), meaning that he has done a crack in the methodology.
The one who observes the sequence of day and night and the dawn which breaks the darkness of night will certainly understand this verse. As the universe is not stable rather it is subjected to changeable and consecutive events. However, any unstable matter has to have a supreme power that changes it; Who is Allah (swt).
On the other hand, this word الْفَجْرِ (dawn) indicates, as well, that the world comes out of its sleep into the enlightening movement that is guided by the truth and is not floundering so that it is a fruitful and beneficial movement.
Hence, the dawn is a sign from Allah (swt) and it is worthy to be sworn by since Allah (swt) does not swear but by the great things.
However, the importance of the dawn does not lessen the value of night. Each of them has a mission which Allah (swt) has willed for it in this worldly life. So, Allah (swt) puts in front of our eyes these interlocutors to teach us that they are signs and are not contradictions, rather they are complementary, and one of the two sides does not dispense with the other.
Moreover, the dawn, which Allah (swt) is swearing by, is not mere the appearance of light which splits the darkness and erases the sign of night, rather it is connected with an act of worshipping which is the prayer of dawn. This prayer by which the Muslim begins his day, through which he takes his strength from Allah (swt), the creator of this life.
Al-Fajr prayer is the most difficult one for the hypocrites because it takes them out of rest and relaxation and deprives them of the pleasure of sleeping.
Hence, Allah (swt) is swearing by the dawn as a time or as a prayer.