A man was sitting with the Prophet ﷺ when another man passed by. He said, "Messenger of Allah, I truly love this man."The Prophet ﷺ asked him, "Have you told him?"He replied, "No."The Prophet ﷺ said, "Tell him."So he caught up with the man and said, "I love you for the sake of Allah."The other man replied, "May the One for whose sake you love me also love you."
أن رجلا كان عند النبي ﷺ، فمر به رجل فقال: يا رسول الله، إني لأحب هذا، فقال له النبي ﷺ: أعلمته؟ قال: لا، قال: أعلمه قال: فلحقه، فقال: إني أحبك في الله، فقال: أحبك الذي أحببتني له.
Narrated by Abu Dawud (5125), Nasai in Amal al-Yawm wal-Layla (182), Ahmad (12514, 12430), and Ibn Hibban graded it sahih (571), as did Hakim (4/171), all of them through routes from Thabit Bunani, from Anas, who related it. Its chain of transmission is sahih. Hakim said, "This is a hadith with a sahih chain of transmission."