I heard (and I think he carried it directly to the Messenger of Allah) him saying: For the people of Medina Dhu'l-Hulaifa is the place for entering upon the state of Ihram, and for (the people coming through the other way, i.e. Syria) it is Juhfa; for the people of Iraq it is Dhat al-'Irq; for the people of Najd it is Qarn (al-Manazil) and for the people of Yemen it is Yalamlam.
سَمِعْتُ أَحْسِبُهُ رَفَعَ إِلَى النَّبِيِّ ﷺ فَقَالَ مُهَلُّ أَهْلِ الْمَدِينَةِ مِنْ ذِي الْحُلَيْفَةِ وَالطَّرِيقُ الآخَرُ الْجُحْفَةُ وَمُهَلُّ أَهْلِ الْعِرَاقِ مِنْ ذَاتِ عِرْقٍ وَمُهَلُّ أَهْلِ نَجْدٍ مِنْ قَرْنٍ وَمُهَلُّ أَهْلِ الْيَمَنِ مِنْ يَلَمْلَمَ