The Messenger of Allah ﷺ said to me, "Do not follow one glance with another, for the first is allowed to you, but the second is not."
قال لي رسول الله ﷺ: لا تتبع النظر النظر، فإن الأولى لك، وليست لك الآخرة.
Ahmad (1369), Bazzar in Kashf Astar (907), Darimi (2751), Tahawi in his Mushkil (1865), Ibn Hibban (5570), and Hakim (3/123) all narrated it through various routes from Hammad bin Salama, from Muhammad bin Ishaq, from Muhammad bin Ibrahim, from Salama bin Abu Tufayl, from Ali, who related it.Some of them mentioned before the hadith, "O Ali, you have a treasure in Paradise, and you are the possessor of its two horns." Hakim said, "Its chain of transmission is sahih."Its chain of transmission is hasan because of Salama bin Abu Tufayl, who is among the men listed in Tajil (403). Muhammad bin Ibrahim and Fitr bin Khalifa narrated from him, and Ibn Hibban confirmed his reliability. His hadith has a firmly established basis, as mentioned before, except that I have not come across an explicit statement from Ibn Ishaq.The meaning of his saying, "and you are the possessor of its two horns," is that you are the possessor of the two horns of Paradise. Others said it means you are the possessor of the two horns of this nation, with "nation" left implied.