ف َبَعْدَ ذَلِكَ سُمِّيَتْ تِلْكَ البِئْرُ بِئْرَ سَبْعٍ، لِأنَّهُما قَطَعا عَهداً وَأقْسَما هُناكَ.
Therefore he called that place Beersheba, because there the two of them took an oath.