Therefore, a person must seek out every means that engenders affection and love among Muslims. It is neither rational nor customary for someone to cooperate with a person he does not love; genuine cooperation in goodness and in righteousness and piety is only possible when love exists. For this reason, loving for the sake of Allah is part of the perfection of faith.

In the hadith of Muʿādh (may Allah be pleased with him) the Prophet ﷺ told him that he loved him, and when Anas said to him, “I love that man,” the Prophet ﷺ asked, “Have you informed him?” This shows that it is a Sunnah: when you love someone you should say to him, “I love you,” because these words sow love in his heart. Once a person knows that you love him, he will love you in return, even though hearts can recognize and harmonize with one another without any speech at all.

The Prophet ﷺ also said, “Souls are like enlisted soldiers: those that recognize one another are harmonious, and those that find one another unfamiliar are at odds.” When love is expressed verbally, however, it increases the affection that already resides in the heart; thus you say, “I love you for Allah’s sake.”

Concerning his words ﷺ, “Do not neglect to say at the close of every prayer…,” the phrase “at the close” (dubur) means the end of the prayer, just as the back (dubur) is the hindmost part of an animal. Another wording of the hadith makes this explicit, indicating that the supplication should be said before one gives the closing salām: “O Allah, help me to remember You, to thank You, and to worship You with excellence.”