Imam Malik (may Allah have mercy on him) said that it reached him that Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) used to say that the prayer should be shortened over a distance like that between Makkah and al-Ta'if, and likewise like that between Makkah and Jeddah, and between Makkah and Usfan. Imam Malik (may Allah have mercy on him) said: This too is four burud.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5395