"And We descend not except by the command of your Lord." Qatadah's interpretation: He said, "This is the statement of Gabriel when he was delayed from the Prophet, peace be upon him, regarding some of the revelation. The Prophet of Allah said to him, 'You have not come until I longed for you.' Gabriel then said, 'And We descend not except by the command of your Lord. To Him belongs that which is before us,'" meaning: of the affairs of the Hereafter, "'and that which is behind us,'" of the affairs of this world; meaning: when we are in the Hereafter. "'And what is between that.'" Al-Kalbi said: It means the Barzakh (interspace); that which is between the two blowings of the Trumpet.
Surah Maryam (from verse 65-72)