From Sahih Muslim (Hadith 3485):
Abu Huraira (Allah be pleased with him) reported:I was in the company of Allah's Messenger (ﷺ) when there came a man and informed him that he had contracted to marry a woman of the Ansar. Thereupon Allah's Messenger (ﷺ) said: Did you cast a glance at her? He said: No. He said: Go and cast a glance at her, for there is something in the eyes of the Ansar
Reference: Muslim 3485