ذَٰلِكَ بِأَنَّ ٱللَّهَ يُولِجُ ٱلَّيۡلَ فِي ٱلنَّهَارِ وَيُولِجُ ٱلنَّهَارَ فِي ٱلَّيۡلِ وَأَنَّ ٱللَّهَ سَمِيعُۢ بَصِيرٞ ٦١
That1 is because Allāh causes the night to enter the day and causes the day to enter the night and because Allāh is Hearing and Seeing.
Translation: Saheeh International (English)
1 i.e., Allāh's capability to give assistance or victory to the oppressed.
Each word's meaning and sound
The helping of the oppressed is because Allah is capable of doing as He wills. From His capabilities is entering the night into the day and the day into the night, by increasing one and decreasing the other. Allah also hears the statements of His servants and knows of their actions; nothing is hidden from Him and He shall requit them accordingly.
Al-Mukhtasar in interpreting the Noble Quran