Of the rights of Allah-SWT , the foremost is the belief in His-SWT Unity. Any one who fails to accept this very basic belief cannot be expected to obey Him-SWT in any way. And of the rights of fellow beings, the rights of parents have the top priority. Allaah-SWT demands in this Ayah not to worship anyone save Him-SWT , and to treat parents kindly.
The Rights of Parents
Whereas the Quran enjoins upon every believer to treat the parents with kindness, many Ahadith expound the blessings and superiority of this act; these also announce that your parents are your Jannah or Hell. It means that their obedience leads to Jannah and disobedience to Hell. It is also added that the retribution for all sins can be postponed but the negligence towards parents is a sin punishable in this world as well.
Parents are not to be Obeyed in Allah-SWT's Defiance
It is a widely acknowledged principle that "no creation will be obeyed in defiance of the Creator". So the obedience to parents will also be within the perimeters of Shari'ah and not in sin or against Allah-SWT's Commands.
Parents to be Treated Kindly even if non Believers
It is obligatory to serve the parents even if they are non Muslims and one must pray for their guidance or worldly comfort. All non obligatory tasks will be subject to their consent. For instance if Jihad is not obligatory in the first degree, and is Fardh-e-Kifayah, one must not go without their permission.
Religious Knowledge and its Propagation
If one possesses obligatory religious knowledge, travelling to become a scholar or to propagate Islam without the permission of parents, will be improper. This also applies to those who neglect their duty towards their wives and children, and set out in the name of preaching.
Treatment to Parents' Friends
Even after the passing away of parents, their friends must be treated as nicely as they were in their lifetime. The Holy Prophet-SW never missed to send gifts to the friends of his-SW beloved wife Khadijah-RAU after she was gone.
Children and their Wealth Belong to Parents
The parents can take of their children's possessions whatever they want without even asking them, as their children's wealth is indeed theirs. Once a person complained about his father to the Holy Prophet-SW that he had taken his money. He was told that he, as well as his possessions, all belonged to his father.
It is also enjoined not to treat both or anyone of the parents as a burden when they grow old, nor to show any negligence in their service, nor speak harshly to them. Rather, one must not even show the slightest of annoyance by word or by action, let alone speak harshly. They must be spoken to affectionately and one must be ever ready to serve them. It is also their right that they must be prayed for in these words: "O' Allaah-SWT ! Have Mercy on them, just as they had taken care of me in my childhood".
Allah-SWT Knows the secrets deep inside the hearts. If wittingly or unwittingly one is rude to them but in his heart he did not wish to do so, it is known to Allaah-SWT . If the intentions are noble, mistakes are forgiven by Him-SWT , provided one feels sorry over his act and mends his ways.
After the parents are the near relatives who must be treated nicely. If they are needy they must be taken care of financially or emotionally, or at least they must be respected, which is their right and not a favour to them. Similarly the destitute in general must be looked after. It is their right to be taken care of, with affection and financial help, and is a duty incumbent on every Muslim. A wayfarer also deserves to be treated well by a Muslim. Allaah-SWT has enjoined on believers to serve the wayfarers as far as they can afford. Again it is not a favour, but their right. And the wealth given by Allaah-SWT must not be squandered away in frivolous and unnecessary ways, for those who do so are the siblings of Satan. To be acknowledged as superior, they waste Allah-SWT's Blessings on evil and wrong pursuits. And Satan is indeed disobedient to Allaah-SWT . However, to fulfill ones genuine needs according to the purse does not fall under squandering. And if one has nothing to offer to a destitute, one must at least speak to him gently, with love and affection, and must never be harsh. These are the values of Islam.
And when it comes to spending, it must be organized and planned. One must never touch the extremes. He must not be so niggardly as if his hands are tied to his own neck, that is, he does not even spend on genuine needs. Nor should he open them so wide that he spends more than the required and wastes his money in prodigality going broke and becoming a destitute himself. In short, a medium must be struck. Rise and fall in income is a common phenomenon. So one must adapt to the situation and spend judiciously according to his means. It is a system of His-SWT Providence whereby He-SWT increases the income for whom He-SWT pleases and constricts it for whom He-SWT Wills. Therefore, in days of affluence one must not squander away in arrogance, and in constraint, must not adopt undesirable means to fulfill his needs. Rather, a balanced attitude in life, in mutual dealings and spending, is the best course of action. Undoubtedly He-SWT is Aware of the condition of His-SWT servants and is constantly watching.