Qala ya noohu innahu laysa min ahlika innahu AAamalun ghayru salihin fala (surah Hud: 46)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(11:46) In response Noah was told: 'Most certainly he is not of your family; verily he is of unrighteous conduct. *49 So do not ask of Me for that concerning which you have no knowledge. I admonish you never to act like the ignorant ones. *50

Qaala yaa Noohu innahoo laisa min ahlika innahoo `amalun ghairu saalihin falaa tas`alni mmaa laisa laka bihee `ilmun inneee a`izuka an takoona minal jaahileen

*49). The import of this Qur'anic verse may best be appreciated by analogy to the limbs on a person's body. A limb may become rotten and a physician may decide to remove it by surgical operation. Now, the patient may ask his doctor not to amputate because it is a part of his body. The natural reply of the physician would be that the rotten limb was not truly a part of his body. Such a reply does not amount to denying, in a literal sense, the obvious fact that the limb is a part of that person's body. What such a statement actually means is that a person's body requires sound and healthy limbs rather than those which are rotten. For rotten limbs are not only useless, they are even able to damage other healthy limbs. In view of the above, it makes sense that that limb be surgically removed. In a similar way a righteous father may be told that his corrupt son is not a part of his family. The biological fact of his being the son of his father is not being negated here. Rather, it is being said that on a moral plane the son has nothing to do with his father's righteous household.
It is also pertinent to remember the context in which the present pronouncement was made. A judgement was needed in the encounter between faith and unbelief so as to determine who had faith and who was devoid of it. The righteous were to be saved and the evil were to be destroyed. The pronouncement was not intended to suggest that those of a certain stock would be saved while others would be destroyed.
By mentioning Noah's son as 'one of unrighteous conduct', the Qur'an draws our attention to another significant fact. A worldly person brings up his children and holds them dear for the simple reason that they happen to be his offspring regardless of their conduct. However, for a believer, the main consideration is how his children actually behave. A believer's view of his children is governed by the conception that his children are God's trust placed in his care such that he may bring them up in a manner that allows them to pursue the end for which God has created man. It is possible, however, that in spite of their best efforts parents may not succeed in the proper upbringing of their children and that the latter, when they grow up, fail to obey their Lord. If this happens, parents should realize that all their efforts have been wasted and that there is no reason for them to hold such children dear to their hearts.
The Qur'an is firm in its suggestion of such an attitude. It is obvious, therefore, that the same holds true for other relatives who are not as close as one's own children. For faith, as we know, is essentially an ideational and moral quality, and people are called believers or men of faith by dint of possessing that quality. It is man's faith which creates affinity between him and all other believers. The essential nexus of this relationship is thus ideational and moral. Those who happen to be a person's kin through blood ties are indeed relatives. If they do not share their faith, however, a believer will fulfil and be required to fulfil only the duties he owes to them on account of the accident of this blood relationship. This relationship, however, is bound to be devoid of the true cordiality and spiritual affinity which characterizes his relationship with believers. And should there be any conflict between belief and unbelief whereby a believer's relatives confront him, the believer is required to treat them exactly as any other unbeliever.
*50). God's observation should not give even the slightest misunderstanding that Noah (peace be on him) in any way lacked the true spirit of faith or that his faith was, to any degree, tainted by Ignorance (Jahiliyah). What perhaps one ought to remember, in order to fully appreciate what is being said here is that even Prophets are human. As human beings, it is not always possible even for them to maintain the very high standards of excellence laid down for men of faith. At some psychologically-charged moment even Prophets, despite their extraordinary spiritual excellence and sublimity, become vulnerable albeit momentarily to human weaknesses. However, as soon as they realize or are made to realize by God that their conduct is falling short of the high standards required of them, they repent. Without the least hesitation or delay, they strive to mend their ways.
In fact there cannot be any better proof of Noah's moral excellence than the present incident mentioned in the Qur'an. Just consider what had happened. Only a few moments previously Noah's son had drowned before his very eyes, something that would have simply shattered his father's whole being. At such an agonizing moment Noah (peace be on him) was reminded by God that his son had identified himself with falsehood rather than with truth. Noah (peace be on him) was told that this feeling that his son belonged to him merely because he was from his loins was a vestige jahiliyah. What is significant is that Noah (peace be on him) immediately re-oriented himself and fully adopted the attitude required of him by Islam, doing so despite the fact that the wound that he had sustained was fresh.