Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: Whoever braided his hair for ihram should shave his head; do not imitate matting (talbid).
This is the authentic (version), from Nafi', from Ibn Umar, from Umar (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9582