So, invoke not with Allah another god lest you should be among those who receive punishment. And warn your tribe of near kindred. And be kind and humble to the believers who follow you.
Here Allah commands (His Prophet) to worship Him alone, with no partner or associate, and tells him that whoever associates others in worship with Him, He will punish them.
Then Allah commands His Messenger to warn his tribe of near kindred, i.e., those who were most closely related to him, and to tell them that nothing couldt nothing could save any of them except for faith in Allah.
Allah also commanded him to be kind and gentle with the believing servants of Allah who followed him, and to disown those who disobeyed him, no matter who they were.
Allah said:
فَإِنْ عَصَوْكَ فَقُلْ إِنِّي بَرِيءٌ مِّمَّا تَعْمَلُونَ