حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ، عَنِ الْعَلاَءِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ اتَّقُوا اللاَّعِنَيْنِ ‏"‏ ‏.‏ قَالُوا وَمَا اللاَّعِنَانِ يَا رَسُولَ اللَّهِ قَالَ ‏"‏ الَّذِي يَتَخَلَّى فِي طَرِيقِ النَّاسِ أَوْ ظِلِّهِمْ ‏"‏ ‏.‏

Narrated Abu Hurairah: The Prophet (sal Allaahu alayhi wa sallam ) as saying : Be on your guard against two things which provoke cursing. They (the hearers) said : Prophet of Allaah ( sal Allaahu alayhi wa sallam), what are these things which provoke cursing: easing in the watering places and on the thoroughfares, and in the shade (of the tree)(where they take shelter and rest). Translation Not Available

Book Ref: Sunan Abi Dawud Book 1 Hadith 25
Web Ref:  Sunan Abi Dawud Book 1 Hadith 25