The Prophet ﷺ said, "Whenever anyone of you offers his prayer he is speaking in private to his Lord. So he should not spit to his right but under his left foot."  

قَالَ النَّبِيُّ ﷺ إِنَّ أَحَدَكُمْ إِذَا صَلَّى يُنَاجِي رَبَّهُ فَلاَ يَتْفِلَنَّ عَنْ يَمِينِهِ وَلَكِنْ تَحْتَ قَدَمِهِ الْيُسْرَى  

The Prophet ﷺ said, "Do the prostration properly and do not put your forearms flat with elbows touching the ground like a dog. And if you want to spit, do not spit in front, nor to the right for the person in prayer is speaking in private to his Lord."  

عَنِ النَّبِيِّ ﷺ قَالَ اعْتَدِلُوا فِي السُّجُودِ وَلاَ يَبْسُطْ ذِرَاعَيْهِ كَالْكَلْبِ وَإِذَا بَزَقَ فَلاَ يَبْزُقَنَّ بَيْنَ يَدَيْهِ وَلاَ عَنْ يَمِينِهِ فَإِنَّهُ يُنَاجِي رَبَّهُ