Be dutiful to your parents

Allah , says:

 الإسرَاء

۞ وَقَضَىٰ رَبُّكَ أَلَّا تَعۡبُدُوٓاْ إِلَّآ إِيَّاهُ وَبِٱلۡوَٲلِدَيۡنِ إِحۡسَـٰنًا‌ۚ إِمَّا يَبۡلُغَنَّ عِندَكَ ٱلۡڪِبَرَ أَحَدُهُمَآ أَوۡ كِلَاهُمَا فَلَا تَقُل لَّهُمَآ أُفٍّ۬ وَلَا تَنۡہَرۡهُمَا وَقُل لَّهُمَا قَوۡلاً۬ ڪَرِيمً۬ا (٢٣) وَٱخۡفِضۡ لَهُمَا جَنَاحَ ٱلذُّلِّ مِنَ ٱلرَّحۡمَةِ وَقُل رَّبِّ ٱرۡحَمۡهُمَا كَمَا رَبَّيَانِى صَغِيرً۬ا (٢٤)

" And your Rabb has decreed that you worship none but Him, and that you be dutiful to your parents. If one of them or both of them attain old age in your life, say not to them a word of disrespect [uff!], nor shout at them, but address them in terms of honour. And lower unto them the wing of submission and humility through mercy, and say: "My Rabb! Bestow on them Your Mercy as they did bring me up when I was a child."" (Qur'an 17:23-24)

Allah , commands all those obligated to obey Him to worship Him, Alone and to observe filial piety and devotion; and He affirms the right of parents upon their offspring immediately after mentioning His right upon His slaves. Then He describes some of the types of filial piety, especially when they become frail and elderly, such as not displaying annoyance with them and not raising one's voice or scolding them, speaking to them in tones of gentleness and kindness and supplicating Allah on their behalf - both while they are alive and after their death.
Benefits Derived from These Verses

1. The obligation of worshipping Allah Alone.
2. The obligation upon every Muslim of filial piety and devotion towards both his parents.
3. The communal responsibility of the whole Muslim society to ensure the rights of parents upon their offspring.

Relevance of These Verses to the Subject of Tawheed
That these Qur'anic verses prove the obligation of worshipping Allah , Alone, without partners.

 Source: 
Kitaab At-Tawheed 
Shaikh Imam Muhammad Abdul-Wahhaab

"The Book of Tawheed"
Compiled by Sameh Strauch