Anas R.A reported that a man was with the
Prophet, may Allah bless him and grant him
peace, when a man passed by him and said,
“O Messenger of Allah, I love this man.” The
Prophet said to him, “Have you informed
him?” He said, “No.” He said, “Inform him,”
and he caught up with him and said, “I love
you for the sake of Allah.” He said, “The One
for whom you love me has made me love
you.” [Abu Dawud]