In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Allaah [The Most High] said:

وَوَصَّيْنَا الْإِنْسَانَ بِوَالِدَيْهِ إِحْسَانًا ۖ حَمَلَتْهُ أُمُّهُ كُرْهًا وَوَضَعَتْهُ كُرْهًا ۖ وَحَمْلُهُ وَفِصَالُهُ ثَلَاثُونَ شَهْرًا ۚ حَتَّىٰ إِذَا بَلَغَ أَشُدَّهُ وَبَلَغَ أَرْبَعِينَ سَنَةً قَالَ رَبِّ أَوْزِعْنِي أَنْ أَشْكُرَ نِعْمَتَكَ الَّتِي أَنْعَمْتَ عَلَيَّ وَعَلَىٰ وَالِدَيَّ وَأَنْ أَعْمَلَ صَالِحًا تَرْضَاهُ وَأَصْلِحْ لِي فِي ذُرِّيَّتِي ۖ إِنِّي تُبْتُ إِلَيْكَ وَإِنِّي مِنَ الْمُسْلِمِينَ

And We have enjoined on man to be dutiful and kind to his parents. His mother bears him with hardship and she brings him forth with hardship, and the bearing of him, and the weaning of him is thirty (30) months, till when he attains full strength and reaches forty years, he says: ‘’My Lord! Grant me the power and ability that I may be grateful for Your Favour which You have bestowed upon me and upon my parents, and that I may do righteous good deeds, such as please You, and make my off-spring good. Truly, I have turned to You in repentance, and truly, I am one of the Muslims [submitting to Your Will].’’ [Surah Al-Ahqaaf. Verse 15]

Imaam As-ASadi [may Allaah have mercy upon him] said:

This is from Allaah’s kindness to His slaves and also that parents deserve to be thanked; therefore, Allaah commanded the off-spring to be dutiful and kind to their two parents- speak to them kindly, spend on them and through other ways of kind treatment. Then Allaah [The Most High] stated the reason behind this command and mentioned what the mother endured due to her child- the severe difficulties she faced during pregnancy, then the great difficulty of childbirth, breast feeding and baby-sitting. These difficulties are not present just for a short period- an hour or two; rather its time period is lengthy [ثَلَاثُونَ شَهْرًا– Thirty months]. And in most cases the period of pregnancy is nine months or (a bit less or more), and then breast feeding during the remaining months after childbirth.

Then Allaah said: [حَتَّىٰ إِذَا بَلَغَ أَشُدَّهُ وَبَلَغَ أَرْبَعِينَ سَنَةً – Till when he (i.e. the person) attains full strength and reaches forty years]– the period in which he exits youth and attains complete [discernment, maturity etc.]; [ قَالَ رَبِّ أَوْزِعْنِي – he says: My Lord! Grant me the power and ability]- Meaning, grant me the ability through speech and deeds [أَنْ أَشْكُرَ نِعْمَتَكَ الَّتِي أَنْعَمْتَ عَلَيَّ وَعَلَىٰ وَالِدَيَّ – that I may be grateful for Your Favour which You have bestowed upon me and upon my parents]- Meaning, to be grateful due to the blessings of Islaam and the things You have given me in the worldly life; and to be grateful to You for granting me the ability to utilise these worldly blessings in acts of obedience to You, because You are the One Who guided me towards them and the One Who preserve them. Therefore, a person should acknowledge the favours of Allaah, declare his inability to thank Allaah the way Allaah deserves and praises Allaah [The Most High] for such favours.

Likewise, the blessings that are bestowed upon the parents are blessings for their offspring, because the children will receive some of those blessings through their parents, especially the blessing of the religion of Islaam, because indeed the righteousness of parents – through knowledge and deeds- is the greatest means for the offspring to be righteous. Then Allaah said (i.e. that this person who has reached the age of forty says): [وَأَنْ أَعْمَلَ صَالِحًا تَرْضَاهُ – And that I may do righteous good deeds, such as please You]; so that such deeds are based on everything that will make them upright and safeguarded against corruption.

Then Allaah said (i.e. that this person who has reached the age of forty says): [وَأَصْلِحْ لِي فِي ذُرِّيَّتِي – And make my off-spring good]-Meaning: Just as I ask for goodness for myself, I also ask Allaah to make the affairs of my off-spring good. [إِنِّي تُبْتُ إِلَيْكَ – Truly, I have turned to You (Allaah) in repentance] from sins and disobedience, and I return to obeying You; [وَإِنِّي مِنَ الْمُسْلِمِينَ – And truly, I am one of the Muslims (submitting to Your Will)]. (1)

Imaam Ash-Shawkaani [may Allaah have mercy upon him] said:
وفي هذه الآية دليل على أنه ينبغي لمن بلغ عمره أربعين سنة أن يستكثر من هذه الدعوات

And in this Ayah is evidence that indeed it is befitting for the one who has reached the age of forty to increase in making these supplications.

رَبِّ أَوْزِعْنِي أَنْ أَشْكُرَ نِعْمَتَكَ الَّتِي أَنْعَمْتَ عَلَيَّ وَعَلَىٰ وَالِدَيَّ وَأَنْ أَعْمَلَ صَالِحًا تَرْضَاهُ وَأَصْلِحْ لِي فِي ذُرِّيَّتِي ۖ إِنِّي تُبْتُ إِلَيْكَ وَإِنِّي مِنَ الْمُسْلِمِينَ

My Lord! Grant me the power and ability that I may be grateful for Your Favour which You have bestowed upon me and upon my parents, and that I may do righteous good deeds, such as please You, and make my off-spring good. Truly, I have turned to You in repentance, and truly, I am one of the Muslims (submitting to Your Will). (2)

Reminder to Myself and all Those Whose Mothers Have Returned to Their Lord

They were the secure places of reassurance- gave their hearts and health to their offspring, wasted their beauty and did not expect anything in return. They were the hearts that released tenderness and support. Whatever is said about them would be very insignificant compared to the comfort they gave. The flood of feelings from them overflowed, as it has always overflowed on us. When fathers were missed for a while, they were the source of all comfort. They carried us heavy by the will of Allaah, nursed us until the time of our weaning, stayed up in the darkness of the night and sacrificed their sleep until we fell asleep. They were the foremost source of love and compassion in the house from whom others learnt to extend love and compassion to others. They exhausted their day through words of encouragement in everything that benefitted us. In childhood, they taught us before we could speak and during our youth they shared their thoughts to guide us to every beneficial affair known to them. They were the first school that prepared us to face the outside world. Indeed, we are unable to do anything to pay them back equally, but we must do our utmost – by the Tawfeeq of Allaah – to supplicate for them constantly and never hesitate to give charity on their behalf. None can replace their love, compassion and comfort after their departure. The eyes shed tears and the heart is grieved, and we will not say except what pleases our Lord. May Allaah grant them and our fathers extensive mercy and enter them into a noble entrance Aameen.

[Ref 1: An Excerpt from ‘Tayseer Ar-Kareem Ar-Rahmaan Fee Tafseer Kalaam Al-Mannaan’. Slightly paraphrased]
[Ref 2: Fat’hul Qadeer 5/22. Slightly paraphrased]