Narrated Anas ibn Malik:

The Messenger of Allah (ﷺ) came to us when I was a boy among the boys. He saluted us and took me by my hand. He then sent me with some message. He himself sat in the shadow of a wall, or he said: near a wall until I returned to him.

حَدَّثَنَا ابْنُ الْمُثَنَّى، حَدَّثَنَا خَالِدٌ، - يَعْنِي ابْنَ الْحَارِثِ - حَدَّثَنَا حُمَيْدٌ، قَالَ قَالَ أَنَسٌ انْتَهَى إِلَيْنَا رَسُولُ اللَّهِ صلى الله عليه وسلم وَأَنَا غُلاَمٌ فِي الْغِلْمَانِ فَسَلَّمَ عَلَيْنَا ثُمَّ أَخَذَ بِيَدِي فَأَرْسَلَنِي بِرِسَالَةٍ وَقَعَدَ فِي ظِلِّ جِدَارٍ - أَوْ قَالَ إِلَى جِدَارٍ - حَتَّى رَجَعْتُ إِلَيْهِ ‏.‏