Muwatta Imam Malik Book of Hajj, Hadith 94

Yahya related to me from Malik from Alqama ibn Abi Alqama that his mother said, "I heard A'isha, the wife of the Prophet ﷺ being asked whether some one in ihram could scratch their body or not, and she said, 'Yes, he can scratch it and do so as hard as he pleases. I would scratch even if my hands were tied and I could only use my feet.' "

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَلْقَمَةَ بْنِ أَبِي عَلْقَمَةَ، عَنْ أُمِّهِ، أَنَّهَا قَالَتْ سَمِعْتُ عَائِشَةَ، زَوْجَ النَّبِيِّ ﷺ تُسْأَلُ عَنِ الْمُحْرِمِ أَيَحُكُّ جَسَدَهُ فَقَالَتْ نَعَمْ فَلْيَحْكُكْهُ وَلْيَشْدُدْ وَلَوْ رُبِطَتْ يَدَاىَ وَلَمْ أَجِدْ إِلاَّ رِجْلَىَّ لَحَكَكْتُ .