And (remember) Ibrahim when he said to his people: "Worship Allah, and have Taqwa of Him, that is better for you if you know. (16)You worship besides Allah only idols, and you only invent falsehood. Verily, those whom you worship besides Allah have no power to give you provision, so seek from Allah your provision, and worship Him, and be grateful to Him. To Him you will be brought back (17)And if you deny, then nations before you have denied. And the duty of the Messenger is only to convey plainly. (18)

Allah tells us how His servant, Messenger and close friend Ibrahim, the Imam of the monotheists, called his people to worship Allah alone, with no partner or associate, to fear Him alone, to seek provision from Him alone, with no partner or associate, to give thanks to Him alone, for He is the One to Whom thanks should be given for the blessings which none can bestow but He. Ibrahim said to his people:

اعْبُدُوا اللَّهَ وَاتَّقُوهُ

(Worship Allah, and have Taqwa of Him,) meaning worship Him and fear Him Alone, with all sincerity.

ذَٰلِكُمْ خَيْرٌ لَكُمْ إِنْ كُنْتُمْ تَعْلَمُونَ

(that is better for you if you know.) if you do that you will attain good in this world and the next, and you will prevent evil from yourselves in this world and the Hereafter.

Then Allah states that the idols which they worshipped were not able to do any harm or any good, and tells them, "You made up names for them and called them gods, but they are created beings just like you." This interpretation was reported by Al-'Awfi from Ibn 'Abbas. It was also the view of Mujahid and As-Suddi. Al-Walibi reported from Ibn 'Abbas: "You invent falsehood, means, you carve idols," which do not have the power to provide for you.

فَابْتَغُوا عِنْدَ اللَّهِ الرِّزْقَ

(so seek from Allah your provision,) This emphasizes the idea of asking Allah Alone. This is like the Ayat:

إِيَّاكَ نَعْبُدُ وَإِيَّاكَ نَسْتَعِينُ

(You (Alone) we worship, and You (Alone) we ask for help.)(1:5) And His saying:

رَبِّ ابْنِ لِي عِنْدَكَ بَيْتًا فِي الْجَنَّةِ

(My Lord! Build for me, with You, a home in Paradise)(66:11). Allah says here:

فَابْتَغُوا

(so seek) meaning, ask for

عِندَ اللَّهِ الرِّزْقَ

(from Allah your provision,) meaning, do not seek it from anyone or anything other than Him, for no one else possesses the power to do anything.

وَاعْبُدُوهُ وَاشْكُرُوا لَهُ

(and worship Him, and be grateful to Him.) Eat from what He has provided and worship Him Alone, and give thanks to Him for the blessings He has given you.

إِلَيْهِ تُرْجَعُونَ 

(To Him you will be brought back.) means, on the Day of Resurrection, when He will reward or punish each person according to his deeds. His saying:

وَإِنْ تُكَذِّبُوا فَقَدْ كَذَّبَ أُمَمٌ مِنْ 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 إِلَّا الْبَلَاغُ 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:

وَإِنْ تُكَذِّبُوا فَقَدْ كَذَّبَ أُمَمٌ مِنْ قَبْلِكُمْ ۖ 

(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.