Allah forbids His believing servants from taking the disbelievers as friends instead of the believers. This includes being friends and associates of the disbelievers, advising them, being intimate with them and exposing the secrets of the believers to them. In another Ayah, Allah said,

﴿لاَّ يَتَّخِذِ الْمُؤْمِنُونَ الْكَـفِرِينَ أَوْلِيَآءَ مِن دُونِ الْمُؤْمِنِينَ وَمَن يَفْعَلْ ذَلِكَ فَلَيْسَ مِنَ اللَّهِ فِي شَىْءٍ إِلاَ أَن تَتَّقُواْ مِنْهُمْ تُقَـةً وَيُحَذِّرْكُمُ اللَّهُ نَفْسَهُ﴾

(Let not the believers take the disbelievers as friends instead of the believers, and whoever does that, will never be helped by Allah in any way, except if you indeed fear a danger from them. And Allah warns you against Himself). meaning, He warns you against His punishment if you fall into what He has prohibited. This is why Allah said here,

﴿أَتُرِيدُونَ أَن تَجْعَلُواْ للَّهِ عَلَيْكُمْ سُلْطَاناً مُّبِيناً﴾

(Do you wish to offer Allah a manifest Sultan against yourselves) meaning, proof against you that warrants receiving His torment. Ibn Abi Hatim narrated that Ibn `Abbas commented;

﴿سُلْطَاناً مُّبِيناً﴾

(manifest Sultan), "The word Sultan in the Qur'an means proof. '' There is an authentic chain of narration for this statement, which is also the saying of Mujahid, `Ikrimah, Sa`id bin Jubayr, Muhammad bin Ka`b Al-Qurazi, Ad-Dahhak, As-Suddi and An-Nadr bin `Arabi.