Sayyiduna Sahl bin Abi Hathmah (may Allah be pleased with him) said: I saw Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him) following the daughter of al-Dahhak with his eyes, so I said: Subhan Allah! You look at her when you are one of the Companions of the Messenger of Allah (peace and blessings be upon him)? He said: I heard the Messenger of Allah (peace and blessings be upon him) say: "When Allah puts into a person's heart (the thought of) proposing marriage to a woman, there is no harm in his looking at her." And Yahya bin Sa'id narrated it from Muhammad bin Sulayman bin Abi Hathmah, from his paternal uncle Sahl bin Abi Hathmah, just as Hafs bin Ghiyath and Yazid bin Harun narrated it from al-Hajjaj.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16550