Allah is Sufficient for His Servant Allah says

أَلَيْسَ اللَّهُ بِكَافٍ عَبْدَهُ

(Is not Allah Sufficient for His servant) Some of them read it "His servants." It means that Allah is Sufficient for the one who worships Him and relies upon Him.

وَيُخَوِّفُونَكَ بِالَّذِينَ مِن دُونِهِ

(Yet they try to frighten you with those besides Him!) means, the idolators tried to scare the Messenger of Allah ﷺ with their idols and gods which they called upon besides Allah out of ignorance and misguidance. Allah says:

وَمَن يُضْلِلِ اللَّهُ فَمَا لَهُ مِنْ هَادٍوَمَن يَهْدِ اللَّهُ فَمَا لَهُ مِن مُّضِلٍّ أَلَيْسَ اللَّهُ بِعَزِيزٍ ذِى انتِقَامٍ

(And whom Allah sends astray, for him there will be no guide. And whomsoever Allah guides, for him there will be no misleader. Is not Allah Almighty, Possessor of Retribution) meaning, whoever relies on Him and turns to Him, will never be forsaken, for He is the Almighty Who cannot be overwhelmed by another, and there is none more severe than Him in exacting retribution on those who disbelieve in Him, associate others in worship with Him and resist His Messenger .

The Idolators admit that Allah is the Sole Creator because Their gods are incapable

وَلَئِن سَأَلْتَهُمْ مَّنْ خَلَقَ السَّمَـوَتِ وَالاٌّرْضَ لَيَقُولُنَّ اللَّهُ

(And verily, if you ask them: "Who created the heavens and the earth" Surely, they will say: "Allah.") means, the idolators used to recognize that Allah was the Creator of all things, but despite that they still worshipped others besides Him, others who had no power to bring benefit or cause harm. Allah said:

قُلْ أَفَرَأَيْتُم مَّا تَدْعُونَ مِن دُونِ اللَّهِ إِنْ أَرَادَنِىَ اللَّهُ بِضُرٍّ هَلْ هُنَّ كَـشِفَـتُ ضُرِّهِ أَوْ أَرَادَنِى بِرَحْمَةٍ هَلْ هُنَّ مُمْسِكَـتُ رَحْمَتِهِ

(Say: "Tell me then, the things that you invoke besides Allah -- if Allah intended some harm for me, could they remove His harm Or if He (Allah) intended some mercy for me, could they withhold His mercy") meaning, they cannot do any of that at all. Here Ibn Abi Hatim recorded a narration from Ibn `Abbas, may Allah be pleased with him, attributing it to the Prophet :

«احْفَظِ اللهَ يَحْفَظْكَ، احْفَظِ اللهَ تَجِدْهُ تُجَاهَكَ، تَعَرَّفْ إِلَى اللهِ فِي الرَّخَاءِ يَعْرِفْكَ فِي الشِّدَّةِ، إِذَا سَأَلْتَ فَاسْأَلِ اللهَ، وَإِذَا اسْتَعَنْتَ فَاسْتَعِنْ بِاللهِ، وَاعْلَمْ أَنَّ الْأُمَّةَ لَوِ اجْتَمَعُوا عَلى أَنْ يَضُرُّوكَ بِشَيْءٍ لَمْ يَكْتُبْهُ اللهُ عَلَيْكَ لَمْ يَضُرُّوكَ، وَلَوِ اجْتَمَعُوا عَلى أَنْ يَنْفَعُوكَ بِشَيْءٍ لَمْ يَكْتُبْهُ اللهُ لَكَ لَمْ يَنْفَعُوكَ، جَفَّتِ الصُّحُفُ وَرُفِعَتِ الْأَقْلَامُ، وَاعْمَلْ للهِ بِالشُّكْرِ فِي الْيَقِينِ.وَاعْلَمْ أَنَّ فِي الصَّبْرِ عَلى مَا تَكْرَهُ خَيْرًا كَثِيرًا، وَأَنَّ النَّصْرَ مَعَ الصَّبْرِ، وَأَنَّ الْفَرَجَ مَعَ الْكَرْبِ، وَأَنَّ مَعَ الْعُسْرِ يُسْرًا»

(Be mindful of Allah and He will protect you; be mindful of Allah and you will find Him ever with you. Turn to Allah in times of ease and He will turn to you in times of difficulty. If you ask anyone for anything, then ask Allah; if you seek help from anyone, then seek help from Allah. Know that even if the entire nation were to come together to do you some harm that Allah has not decreed for you, they will never be able to harm you, and if they were to come together to do you some good that Allah has not decreed for you, they will never be able to do that. The pages have dried and the pens have been lifted. Strive for the sake of Allah with thankfulness and firm conviction, and know that in patiently persevering with regard to something that you dislike there is much goodness. Victory comes with patience, a way out comes from difficulty and with hardship comes ease.)

قُلْ حَسْبِىَ اللَّهُ

(Say: "Sufficient for me is Allah...") means, `Allah is enough for me.'

عَلَيْهِ تَوَكَّلْتُ وَعَلَيْهِ فَلْيَتَوَكَّلِ الْمُتَوَكِّلُونَ

(In Him I put my trust, and let all those that trust, put their trust in Him.) 12: 67 This is like what Hud, peace be upon him, said to his people:

إِن نَّقُولُ إِلاَّ اعْتَرَاكَ بَعْضُ ءَالِهَتِنَا بِسُوءٍ قَالَ إِنِّى أُشْهِدُ اللَّهِ وَاشْهَدُواْ أَنِّى بَرِىءٌ مِّمَّا تُشْرِكُونَ - مِن دُونِهِ فَكِيدُونِى جَمِيعًا ثُمَّ لاَ تُنظِرُونِ - إِنِّى تَوَكَّلْتُ عَلَى اللَّهِ رَبِّى وَرَبِّكُمْ مَّا مِن دَآبَّةٍ إِلاَّ هُوَ ءاخِذٌ بِنَاصِيَتِهَآ إِنَّ رَبِّى عَلَى صِرَطٍ مُّسْتَقِيمٍ

("All that we say is that some of our gods have seized you with evil. " He said: "I call Allah to witness and bear you witness that I am free from that which you ascribe as partners in worship, with Him. So plot against me, all of you, and give me no respite. I put my trust in Allah, my Lord and your Lord! There is not a moving creature but He has the grasp of its forelock. Verily, my Lord is on the straight path.")(11:54-56).

قُلْ يقَوْمِ اعْمَلُواْ عَلَى مَكَانَتِكُـمْ

(Say: "O My people! Work according to your way...") This is a threat and a warning.

إِنِّى عَـمِلٌ

(I am working) means, `according to my way.'

فَسَوْفَ تَعْلَمُونَ

(Then you will come to know) means, you will learn the consequences.

مَن يَأْتِيهِ عَذَابٌ يُخْزِيهِ

(To whom comes a disgracing torment,) means, in this world,

وَيَحِلُّ عَلَيْهِ عَذَابٌ مُّقِيمٌ

(and on whom descends an everlasting torment.) means, ongoing and eternal, with no escape, which will come on the Day of Resurrection. We seek refuge with Allah from that.