Al-'Ankabut 29:18

Wa-in tukaththiboo faqad kaththabaomamun min qablikum wama AAala arrasooliilla albalaghu almubeen

And if you [people] deny [the message] - already nations before you have denied. And there is not upon the Messenger except [the duty of] clear notification.

And if you reject me, then many nations have rejected their messengers before you. The messenger has no more obligation than to convey the message clearly.”