I never saw the Messenger of Allah ﷺ praying in front of a stick, a pillar, or a tree, without having it opposite his right or left eyebrow, and not facing it directly. (Using translation from Abū Dāʾūd 693)
أَنَّهُ قَالَ مَا رَأَيْتُ رَسُولَ اللهِ ﷺ صَلَّى إِلَى عَمُودٍ وَلَا عُودٍ وَلَا شَجَرَةٍ إِلَّا جَعَلَهُ عَلَى حَاجِبِهِ الْأَيْمَنِ وَالْأَيْسَرِ وَلَا يَصْمُدُ لَهُ صَمْدًا