So, it is alike to them whether you warn them or do not warn them; (although it is your mission to warn them and you do it without any neglect) they will not believe
And it is all the same to them whether you warn them or do not warn them, they will not believe (for they have deliberately shut their eyes and ears to the truth)
Whether you warn them or do not warn them, it is all the same; they will not believe!
Sayyed Abbas Sadr-Ameli
And the same is to them whether you warn them or you do not warn them, they do not believe.
Al-muntakhab fi tafsir al-Qur'an al-Karim
Such persons O Muhammad whether you warn them of impending danger and misfortunes or you do not, it is one and the same; they counsel deaf and will not open their hearts' ears nor their minds’ eyes