وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ عَبْدَ اللَّهِ بْنَ عَبَّاسٍ، كَانَ يَقْصُرُ الصَّلاَةَ فِي مِثْلِ مَا بَيْنَ مَكَّةَ وَالطَّائِفِ وَفِي مِثْلِ مَا بَيْنَ مَكَّةَ وَعُسْفَانَ وَفِي مِثْلِ مَا بَيْنَ مَكَّةَ وَجُدَّةَ ‏.‏ قَالَ مَالِكٌ وَذَلِكَ أَرْبَعَةُ بُرُدٍ وَذَلِكَ أَحَبُّ مَا تُقْصَرُ إِلَىَّ فِيهِ الصَّلاَةُ ‏.‏ قَالَ مَالِكٌ لاَ يَقْصُرُ الَّذِي يُرِيدُ السَّفَرَ الصَّلاَةَ حَتَّى يَخْرُجَ مِنْ بُيُوتِ الْقَرْيَةِ وَلاَ يُتِمُّ حَتَّى يَدْخُلَ أَوَّلَ بُيُوتِ الْقَرْيَةِ أَوْ يُقَارِبُ ذَلِكَ ‏.‏

Yahya related to me from Malik that he had heard that Abdullahibn Abbas used to shorten the prayer when he travelled a distanceequivalent to that between Makka and Ta'if, and that between Makka andUsfan and that between Makka and Jedda. Malik said, "That isfour mail-stages, and to me that is the most preferable distance forshortening the prayer." Malik said, "Someone who intends totravel does not shorten the prayer until he has left the houses of thevillage. And he does not do it in full until he comes to the firsthouses of the village, or is nearby." Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 345
Web Ref:  Muwatta Imam Malik Book 9 Hadith 17