Muwatta Malik #935
Hajj
The Arabic includes the chain of narration (sanad) and the collector's commentary; the English translation shows the Prophet's words only.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ لَقِيَ رَجُلاً مِنْ أَهْلِهِ يُقَالُ لَهُ الْمُجَبَّرُ قَدْ أَفَاضَ وَلَمْ يَحْلِقْ وَلَمْ يُقَصِّرْ جَهِلَ ذَلِكَ فَأَمَرَهُ عَبْدُ اللَّهِ أَنْ يَرْجِعَ فَيَحْلِقَ أَوْ يُقَصِّرَ ثُمَّ يَرْجِعَ إِلَى الْبَيْتِ فَيُفِيضَ .
Yahya related to me from Malik from Nafi that Abdullah ibn Umar
once met a relative of his called al-Mujabbar who had done the tawaf
al-ifada but, out of ignorance, had not shaved his head or cut his
hair. Abdullah told him to go back and shave his head or cut his hair,
and then go back and do the tawaf al-ifada.
About Muwatta Malik
This hadith is #935 from Muwatta Malik, in the Book of Hajj.