—let him speak what is good, or else remain silent.

Third: be mindful of Allah in your private self and in your heart. Look deep inside and see whether there lurks any shirk (associating partners with Allah), ostentation, deviation, rancour toward the believers, hatred, aversion, love for the disbelievers, or anything else that Allah does not approve.

Watch over your heart; examine it constantly. Allah says: “We certainly created man, and We know what his own soul whispers within him” (Qāf 16)—even before he gives those thoughts voice.

Therefore observe Allah in these three arenas: in your actions, in your speech, and in your innermost thoughts—your very heart—so that your vigilance (murāqabah) may be complete. For this reason, when the Prophet (peace and blessings be upon him) was asked about excellence (ihsān) he replied, “That you worship Allah as though you see Him; and if you do not see Him, He surely sees you.”

Worship Allah as though you behold Him with your very eyes; if you cannot reach that level, then descend to the second: “for He surely sees you.”

The first is worship motivated by longing and hope—worshipping Allah as though you see Him. The second is worship prompted by awe and fear; hence he said, “and if you do not see Him, He surely sees you.”

You must therefore keep watch over your Lord and know that Allah is keeping watch over you. Whatever you say, do, or conceal in the secrecy of your heart, Allah Most High is fully aware of it. The author—may Allah have mercy on him—has cited verses that testify to this, beginning with the verse we have already mentioned: Allah’s words to His Prophet Muhammad (peace and blessings be upon him), “And rely upon the Almighty, the Most Merciful, the One who sees you when …”