( ذلك ) أي : ذلك النصر ( بأن الله ) القادر على ما يشاء ، فمن قدرته أنه : ( يولج الليل في النهار ويولج النهار في الليل وأن الله سميع بصير )
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.