Showing Kindness to Parents

Answer – and Allah is the One who grants success: Kindness (iḥsān) is the opposite of abuse (isā’ah). The least level of kindness is to withhold harm and to deal justly with people against your own self; whatever goes beyond that is bounty and kindness.
Based on this, the child must avoid anything by which his father is harmed. From here comes the narration from the Prophet, May Allah bless him and his family and grant them peace, that he commanded one of the warriors in one of the battles to return to his parents, and ordered him to make them laugh just as he had made them weep, for that warrior had set out with the Prophet, May Allah bless him and his family and grant them peace, for that campaign while his parents were crying.
And among the things by which the parents are harmed is what Allah has forbidden of sighing at them in annoyance, feeling disgust towards them, treating them harshly, and shouting at them, as found in His saying: “So do not say to them even ‘uff,’ nor rebuke them, but speak to them with gracious words.” [Al-Isrā’:23]
It is also necessary to show them reverence and magnification, and to supplicate for them with the supplication which we have been commanded to say at the end of the previous verse: “And be humble to them out of mercy and say, ‘My Lord, have mercy on them as they raised me when I was small.’” [Al-Isrā’:24]
It is likewise necessary to fulfill their needs if they are in need: he must spend on them if they are in need, and share with them from that with which Allah has provided him. For it is not part of dutifulness that the child sleeps full while his parents sleep hungry.
Then, after that, what is required of him is what custom and habit have established, such as visits and the like, including giving them something as a present; and he repeats that according to what is customary.
Thus, everything we have mentioned is regarded, in common customs and usages, as kindness; and whoever abandons it is not considered a doer of kindness.
As for what is obligatory of kindness towards the relatives by blood (arḥām), it is to refrain from harming them, to be just with them, and to maintain visits according to what customs have established, as well as giving them something and providing them gifts if that exists in the customs; each person in accordance with his ease or hardship; likewise hosting them according to what is known in custom and usage; and supporting them in what is right—up to all that people’s customs and usages include in that regard.
There are also rights to which the Sacred Law and custom have urged us, such as visiting him if he falls ill, saying “yarḥamuk Allāh” to him if he sneezes, asking about him if he is absent, following his funeral if he dies, consoling him if he is afflicted, congratulating him if a blessing befalls him, and so on. And although such matters are mentioned among the general rights of the believers, relatives by blood are even more entitled to them.

Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2