﴿ وَلَا يَصُدُّنَّكَ عَنْ ءَايَٰتِ ٱللَّهِ بَعْدَ إِذْ أُنزِلَتْ إِلَيْكَ ۖ وَٱدْعُ إِلَىٰ رَبِّكَ ۖ وَلَا تَكُونَنَّ مِنَ ٱلْمُشْرِكِينَ ﴾

“and never let them turn thee away from God’s messages after they have been bestowed upon thee from on high: instead summon [all men] to thy Sustainer. And never be of those who ascribe divinity to aught but Him,”

And never let them bar you yasuddunnaka is actually yasuddūnannaka but the nūn of the indicative ending has been omitted because of the apocopating particle lā as has the wāw of the third person plural subject of the verb because of its coming together with an unvocalised nūn from God’s signs after they have been revealed to you in other words do not consult with them in such matters and summon people to your Lord by affirming His Oneness and worshipping Him and never be of the idolaters by supporting them lā takūnanna the apocopating particle does not affect the ending of the verb here because of its invariability.