"O my people, if my position is burdensome to you," by inviting you to Allah, the Mighty and Majestic, "and my reminding you of the signs of Allah, then upon Allah I have relied. So resolve upon your plan and [call upon] your associates," meaning: and gather your associates. "Then let not your plan be obscure to you," meaning: in secrecy; let it be done openly.
﴿يَا قَوْمِ إِنْ كَانَ كَبُرَ عَلَيْكُم مقَامي﴾ بِالدُّعَاءِ إِلَى اللَّهِ ﷿ ﴿وَتَذْكِيرِي بِآيَاتِ اللَّهِ فَعَلَى اللَّهِ توكلت فَأَجْمعُوا أَمركُم وشركاءكم﴾ أَيْ: وَأَجْمِعُوا شُرَكَاءَكُمْ ﴿ثُمَّ لَا يكن أَمركُم عَلَيْكُم غمَّة﴾ أَيْ: فِي سِتْرٍ، لِيَكُنْ ذَلِكَ عَلانِيَةً.