It is actually this Hadith:
Narrated `Ubaid Ibn Juraij :ra::
I asked `Abdullah bin `Umar :ra:, "O Abu `Abdur-Rahman! I saw you doing four things which I never saw being done by anyone of you companions?" `Abdullah bin `Umar said, "What are those, O Ibn Juraij?" I said, "I never saw you touching any corner of the Ka`ba except these (two) facing south (Yemen) and I saw you wearing shoes made of tanned leather and dyeing your hair with Hinna (a kind of red dye). I also noticed that whenever you were in Mecca, the people assume Ihram on seeing the new moon crescent (1st of Dhul-Hijja) while you did not assume the Ihlal (Ihram) -(Ihram is also called Ihlal which means 'Loud calling' because a Muhrim has to recite Talbiya aloud when assuming the state of Ihram) - till the 8th of Dhul-Hijja (Day of Tarwiya). `Abdullah replied, "Regarding the corners of Ka`ba, I never saw Allah's Messenger (ﷺ) touching except those facing south (Yemen) and regarding the tanned leather shoes, no doubt I saw Allah's Messenger (ﷺ) wearing non-hairy shoes and he used to perform ablution while wearing the shoes (i.e. wash his feet and then put on the shoes). So I love to wear similar shoes. And about the dyeing of hair with Hinna; no doubt I saw Allah's Messenger (ﷺ) dyeing his hair with it and that is why I like to dye (my hair with it). Regarding Ihlal, I did not see Allah's Messenger (ﷺ) assuming Ihlal till he set out for Hajj (on the 8th of Dhul-Hijja).
|| : Sahih al-Bukhari 166
|| : Book 4, Hadith 32
|USC-MSA web (English) reference
|| : Vol. 1, Book 4, Hadith 167
| (deprecated numbering scheme)