‘Ata’ b. Yasar told that when God’s messenger was in the mosque a man whose head and beard were dishevelled entered, and God’s messenger pointed his hand at him as though he were ordering him to arrange his hair and his beard. When he had done so and returned, God's messenger said, “Is this not better than that one of you should come with his head dishevelled, as though he were a devil ?” Malik transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَن عطاءِ بن يسارٍ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي الْمَسْجِدِ فَدَخَلَ رَجُلٌ ثَائِرُ الرَّأْسِ وَاللِّحْيَةِ فَأَشَارَ إِلَيْهِ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِيَدِهِ كَأَنَّهُ يَأْمُرُهُ بِإِصْلَاحِ شَعْرِهِ وَلِحْيَتِهِ فَفَعَلَ ثُمَّ رَجَعَ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَلَيْسَ هَذَا خَيْرًا مِنْ أَنْ يَأْتِيَ أَحَدُكُمْ وَهُوَ ثَائِرُ الرَّأْسِ كَأَنَّهُ شَيْطَان» . رَوَاهُ مَالك
sunnah.com