“And if We willed, We could show them to you, and you would know them by their mark; but you will surely recognize them by the tenor of their speech. Allah knows your deeds. * And We will surely test you until We make evident those among you who strive and remain steadfast, and We will test your affairs.”

“And if We willed, We could show them to you, and you would know them by their mark”—that is, by the signs upon them, which are like brands upon their faces. “But you will surely recognize them by the tenor of their speech”—that is, what lies within their hearts will inevitably surface and become apparent through slips of their tongues. Tongues are the ladles of hearts, revealing the good and evil contained within them. “Allah knows your deeds,” and He will recompense you for them.

He then mentioned the greatest trial by which He tests His servants—striving in Allah’s cause—and said: “And We will surely test you”—that is, We will test your faith and steadfastness—“until We make evident those among you who strive and remain steadfast, and We will test your affairs.” Whoever obeys Allah’s command and strives in His cause to support His religion and exalt His word is a true believer. Whoever is remiss in doing so has a deficiency in his faith.