Ibn al-Zubayr said: When this verse was revealed, Umar thereafter spoke so softly to the Prophet, peace and blessings be upon him, that the Prophet, peace and blessings be upon him, would have to ask him to repeat himself. This was because he lowered his voice. So Allah Most High revealed: “Indeed, those who lower their voices”—that is, who lower “their voices in the presence of the Messenger of Allah” out of reverence for him—“are the ones whose hearts Allah has tested for piety”: He has tested and purified them, just as gold is tested by fire, from which its pure substance emerges. “For them is forgiveness and a tremendous reward.”

“Indeed, most of those who call out to you from behind the private chambers do not understand.” (4)