Ja'far bin Awn narrates from Hisham bin Sa'd that between Makkah and Sarif there is a distance of ten miles. Combining two prayers because of an excuse (travel) is well known; it is established from the Companions (may Allah be pleased with them), the Successors, and the Prophet (peace and blessings be upon him) as well, and moreover there is agreement on combining the prayers at Arafah and Muzdalifah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5536