Take not as supporters your fathers and your brothers (Surah At-Taubah 9: 23-24)

Say: If your fathers, your sons, your brothers, your spouses, your kindred, the wealth that you have gained, the commerce in which you fear a decline, and the dwellings in which you delight are dearer to you than Allah and His Messenger, and striving hard and fighting in His cause, then wait until Allah brings about His decision (torment). And Allah guides not the people who are rebellious.  (Surah At-Taubah 9: 24)


The Prohibition of taking the Idolators as Supporters, even with Relatives

Allah commands shunning the disbelievers, even if they are one's parents or children, and prohibits taking them as supporters if they choose disbelief instead of faith. Allah warns,

You will not find any people who believe in Allah and the Last Day, making friendship with those who oppose Allah and His Messenger, even though they were their fathers or their sons or their brothers or their kindred (people). For such He has written (predetermined) faith in their hearts, and strengthened them with a Ruh (proof, light and true guidance) from Himself. And He will admit them to Gardens (Paradise) under which rivers flow. [Surah Al-Mujadilah 58: 22]

Al-Hafiz Al-Bayhaqi recorded that `Abdullah bin Shawdhab said, "The father of Abu `Ubaydah bin Al-Jarrah (Radhi Allahu Anhu)  was repeatedly praising the idols to his son on the day of Badr, and Abu `Ubaydah kept avoiding him. When Al-Jarrah persisted, his son Abu `Ubaydah headed towards him and killed him. Allah revealed this Ayah in his case,

You will not find any people who believe in Allah and the Last Day, making friendship with those who oppose Allah and His Messenger.''[Surah Al-Mujadilah 58: 22] Allah commanded His Messenger (Sallallahu Alayhi wa Sallam) to warn those who prefer their family, relatives or tribe to Allah, His Messenger (Sallallahu Alayhi wa Sallam) and Jihad in His cause,

Say: If your fathers, your sons, your brothers, your wives, your kindred, the wealth that you have gained, amassed and collected, the commerce in which you fear a decline, and the dwellings in which you delight, and prefer and love because they are comfortable and good. If all these things,

are dearer to you than Allah and His Messenger, and striving hard and fighting in His cause, then wait... for what will befall you of Allah's punishment and torment,

until Allah brings about His decision. And Allah guides not the people who are rebellious.

Imam Ahmad recorded that Zuhrah bin Ma`bad said that his grandfather said, "We were with the Messenger of Allah (Sallallahu Alayhi wa Sallam) , while he was holding the hand of `Umar bin Al-Khattab. `Umar (Radhi Allahu Anhu) said, `By Allah! You, O Messenger of Allah, are dearer to me than everything, except for myself.' The Messenger of Allah (Sallallahu Alayhi wa Sallam) said,  

None among you will attain faith until I become dearer to him than even himself. Umar (Radhi Allahu Anhu) said, `Verily, now, you are dearer to me than myself, by Allah!' The Messenger of Allah (Sallallahu Alayhi wa Sallam) said,

Now, O `Umar!'' Al-Bukhari also collected this Hadith. Imam Ahmad and Abu Dawud (this is the version of Abu Dawud) recorded that Ibn `Umar (Radhi Allahu Anhuma) said, "I heard the Messenger of Allah (Sallallahu Alayhi wa Sallam) saying,

If you transact in `Iynah (a type of Riba), follow the tails of cows (tilling the land), become content with agriculture and abandoned Jihad, Allah will send on you disgrace that He will not remove until, you return to your religion.''  


Source: Tafsir ibn Kathir (Abridged)