Surah Al Ankabut Tafseer

وَإِن تُكَذِّبُوا فَقَدْ كَذَّبَ أُمَمٌ مِّن قَبْلِكُمْ

And if you deny, then nations before you have denied.

means, `you have heard what happened to them by way of punishment for opposing the Messengers.'

وَمَا عَلَى الرَّسُولِ إِلاَّ الْبَلَغُ الْمُبِينُ

And the duty of the Messenger is only to convey plainly.

All the Messengers have to do is to convey the Message as Allah has commanded them. Allah guides whoever He wills and leaves astray whoever He wills, so strive to be among the blessed.

Qatadah said concerning the Ayah:

(And if you deny, then nations before you have denied),

"These are words of consolation to His Prophet, peace be upon him."

This suggestion by Qatadah implies that the narrative (about Ibrahim) is interrupted here, and resumes with the words "And nothing was the answer of (Ibrahim's) people..." in Ayah 24.

This was also stated by Ibn Jarir. From the context it appears that Ibrahim, peace be upon him, said all of what is in this section. Here he establishes proof against them that the Resurrection will indeed come to pass, because at the end of this passage it says:

فَمَا كَانَ جَوَابَ قَوْمِهِ

("And nothing was the answer of his people..."). (29:24)

And Allah knows best