The Messenger of Allah ﷺ said, "Do not follow one glance with another, for the first is allowed to you but not the second."
حدثنا وكيع حدثنا شريك عن أبي ربيعة
قال رسول الله ﷺ لا تتبع النظرة النظرة فإنما لك الأولى وليست لك الآخرة
Its isnad is hasan, mentioned previously at 1369. It is found in Abu Dawud 2/246 number 2149, in the Book of Marriage, and Tirmidhi in the Book of Manners 5/101 number 2777, where he said, hasan gharib. Hakim graded it sahih 2/194, and Dhahabi agreed with him. It is also found in Darimi 2/386 number 2709, and Bayhaqi 7/90, all of them in the Book of Marriage.