[Say: Shall I seek a lord other than Allah, while He is the Lord of all things?] This is a response from Allah to the polytheists when they invited the Prophet to worship what his forefathers used to worship. [And no bearer of burdens shall bear the burden of another.] The 'wizr' is the sin; meaning: no one shall carry the sin of another.
﴿قُلْ أَغَيْرَ اللَّهِ أَبْغِي رَبًّا وَهُوَ رب كل شَيْء﴾ وَهَذَا جوابٌ مِنَ اللَّهِ لِلْمُشْرِكِينَ، حَيْثُ دَعَوُا النَّبِيَّ إِلَى أَنْ يَعْبُدَ مَا كَانَ يَعْبُدُ آبَاؤُهُ ﴿وَلا تَزِرُ وَازِرَةٌ وِزْرَ أُخْرَى﴾ الْوِزْرُ: الذَّنْبُ؛ يَقُولُ: لَا يَحْمِلُ أحدٌ ذَنْب أحدٍ.