I am not a religious teacher to interpret the verses of Allah swt from the Al-Quran. But I would like to share some of what I have extracted from the Al-Quran for us to think and reflect on our daily lives... regarding respecting parents...
And We have enjoined man to do good to his parents – his mother bears him with pain, and brings him forth with pain, and his bearing and weaning takes thirty months: until when he reaches the age of strength and reaches the age of fourty, he says: My Lord! Grant me that I may give thanks for the favour which You bestowed on me and on my parents, and that I may do righteous deeds which may please You, can be gracious to me with regards to my offspring; surely I turn to You and I am of those who submit (in Islam) (Surah Al-Ahqaf: 15)
Say: Come, I will recite to you what my Lord has forbidden to you: that you associate not anything as partner with Him. And (He orders you) doing good to your parents, and you kill not your children for fear of poverty” – We provide provisions for you and for them also – “And you come not near to indecencies whether it is open or hidden, and that you kill not any person whom Allah has forbidden you to kill, except by way of justice.” This He has commanded you, that you may understand. (Surah Al-An’am: 151)
...what more if they are elderly parents. Like it or not we will one day come to this stage.
Allah is He Who created you from a weak state, and then after the weak state, He gave you strength, and then after the strength, He gave you weakness and grey hair. He creates what He likes for He is the All-Knowing, and All-Powerful (Surah Al-Rum: 54).
And your Lord has ruled that you worship none but Him alone, and that you do good to your parents. If one or both of them reach old age while you are alive, then say not to them a word of disrespect, or scold them, but say a generous word to them. And act humbly to them in mercy, and say, ‘My Lord, have mercy on them, since they cared for me when I was small.” (Surah Al-Isra’: 23-24).
He (Zakariyya) said, “My Lord! Surely my bones are weakened, and grey hair has spread on my head, and my Lord! Never has my prayer unto You remained unanswered. (Surah Maryam: 4).
And whomsoever We cause to live long, We reverse him in creation. Do they not understand? (Surah Yaasin: 68).
And Allah creates you, then He causes you to die, and some of you are caused to be returned to a feeble age, so that after knowing somewhat, he may know nothing. Surely Allah is Knowing, Powerful (Surah Al-Nahl: 70).
So dear friends, be thankful to our parents whether they are still alive or has left us. Respect the elderly. Before reaching this stage, love and treat your children and family members because of Allah, insyaAllah you will be well treated at old age.