ENOfficial
Buraida reported God's Messenger as saying to ‘Ali, “Do not give a second look, ‘Ali, for while you are not to blame for the first you have no right to the second.” Ahmad, Tirmidhi, Abu Dawud and Darimi transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ بُرَيْدَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لِعَلِيٍّ: «يَا عَلِيُّ لَا تُتْبِعِ النَّظْرَةَ النَّظْرَةَ فَإِنَّ لَكَ الْأُولَى وَلَيْسَتْ لَكَ الْآخِرَةُ» . رَوَاهُ أَحْمَدُ وَالتِّرْمِذِيُّ وَأَبُو دَاوُدَ والدارمي
sunnah.com