The Messenger of Allah ﷺ said: Tie the horses, rub down their forelocks and their buttocks (or he said: Their rumps), and put things on their necks, but do not put bowstrings.  

عَنْ أَبِي وَهْبٍ الْجُشَمِيِّ وَكَانَتْ لَهُ صُحْبَةٌ قَالَ قَالَ رَسُولُ اللَّهِ ﷺ ارْتَبِطُوا الْخَيْلَ وَامْسَحُوا بِنَوَاصِيهَا وَأَعْجَازِهَا أَوْ قَالَ أَكْفَالِهَا وَقَلِّدُوهَا وَلاَ تُقَلِّدُوهَا الأَوْتَارَ