Mishkat al-Masabih 10 The Rites of Pilgrimage كتاب المناسك 138

وَعَنِ ابْنِ عَبَّاسٍ قَالَ: قَالَ لِي مُعَاوِيَةُ: إِنِّي قَصَّرْتُ مِنْ رَأْسِ النَّبِيِّ صلى الله عَلَيْهِ وَسلم عِنْد الْمَرْوَة بمشقص

Ibn ‘Abbas said that Mu’awiya told him he had clipped some hair from the Prophet’s head at al-Marwa with a broad, iron arrowhead. Bukhari and Muslim.