Don't have estranged relations (with the others) and don't nurse enmity and don't enter into a transaction when the other (has already entered) and be fellow-brothers and servants of Allah.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ تَهَجَّرُوا وَلاَ تَدَابَرُوا وَلاَ تَحَسَّسُوا وَلاَ يَبِعْ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ وَكُونُوا عِبَادَ اللَّهِ إِخْوَانًا
Yahya related to me from Malik from Nafi from Abdullah ibn Umar that the Messenger of Allah ﷺ said, "Do not let any of you bid against each other."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَبِعْ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ
"لَا تَهَجَّرُوا، وَلَا تَدَابَرُوا، وَلَا تَحَسَّسُوا، وَلَا يَبِعْ بَعْضُكُم عَلَى بَيْعِ بَعْضٍ، وكُونُوا عبادَ الله إِخْوَانًا".