Mishkat al-Masabih 3 Purification كتاب الطهارة 67

وَعَنْ مُعَاذٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: ” اتَّقُوا الْمَلَاعِنَ الثَّلَاثَةَ: الْبَرَازَ فِي الْمَوَارِدِ وَقَارِعَةِ الطَّرِيقِ وَالظِّلِّ ” . رَوَاهُ أَبُو دَاوُد وَابْن مَاجَه

Mu’adh reported God’s messenger as saying, “Guard against the three things which produce cursing: relieving oneself in watering-places, in the middle of the road, and in the shade.” Abu Dawud and Ibn Majah transmitted it.