It was narrated from Abu Hurairah that the Prophet ﷺ performed Wudu', and when he had performed Istinja' he rubbed his hand on the ground. (Using translation from Nasāʾī 50)  

أَنَّ النَّبِيَّ ﷺ «تَوَضَّأَ فَلَمَّا اسْتَنْجَى دَلَكَ يَدَهُ بِالْأَرْضِ»