The younger brother has to respect and obey his older brother who is of sound mind
Question

Do I have to obey my eldest brother?
There is me, my mother, my father and my eldest brother.
My mother is living with us and my father is working abroad (so he is not with us).
If my eldest brother commands me to do things such as “clean up” or he will question me like “What are you doing in your studies?” and when I refuse to answer he will say “you have to (islamically) I am the eldest” – even though my mother is the eldest one living with us.
So my question is this – Is it FARD to obey my eldest brothers commands or questions i.e. “what are you doing? Where are you going?” or “clean up the kitchen”
So is it fard in this particular situation to obey his commands AND answer his questions? reconciliation with him did not work when I tried it. Also if my father was here – would it be fard in that situation?
I obey my parents – I just dont obey him to avoid argueing and sinning.
Praise be to Allah.Older siblings should show compassion towards younger siblings, and younger siblings should respect older siblings, and there should be among them an atmosphere of harmony, mutual love and sincerity, and an absence of dissent.
At-Tirmidhi (1919) narrated from Anas that the Prophet (blessings and peace of Allah be upon him) said: “He is not one of us who does not show compassion towards our younger ones and show respect to our older ones.”
Classed as saheeh by al-Albaani in Saheeh at-Tirmidhi.
Al-Mannaawi (may Allah have mercy on him) said:
The one who is older should be given his due of honour and respect. End quote.
Fayd al-Qadeer (5/388)
The older brother has some share of guardianship over his younger brother.
Ash-Shirwaani said in his Haashiyah (3/21):
Those who have guardianship and a responsibility to discipline a person include his mother and his older brother. End quote.
Al-Jamal said in his Haashiyah (4/426):
It may be understood that everyone who has guardianship and a responsibility to discipline a person is like the father, such as his paternal uncle and his brother. End quote.
So long as your father is travelling, custom dictates that the older brother plays the role of the father in the house, so he is responsible for the family and for disciplining his younger brothers and following up on their education, and so on. So they have to respect him and obey him.
But if the father is with you in the house, then it is the father who runs the household and is responsible for every individual in it. If he instructs you to obey your older brother, then you have to obey him. The same applies if he does not explicitly instruct you to do that, but he likes you to do that, or the custom in your country dictates that.
Undoubtedly the father would like his children to love one another and cooperate, and not to disagree.
The Messenger (blessings and peace of Allah be upon him) sent Mu‘aadh ibn Jabal and Abu Moosa al-Ash‘ari as governors of Yemen, each of them in charge of some part of the land, and he said to them: “Co-operate and do not disagree.” Agreed upon.
If the older brother follows up on his younger brother’s studies and asks him how he is doing, this is something that is indicative of his mature thinking and sound reasoning, and the younger brother should pay attention to that, and answer his questions and obey him. He should not get angry when he asks questions and follows up with him, because he is only doing that out of concern for his brother’s interests and because he loves what is good for him.
The same applies if he tells him to clean the house, or help his mother and sisters in doing that. He has the right to make that request, and the younger brother has to obey him, because he is telling him to do something that is right and good, and encouraging him to obey his mother and help his sisters, and all of that is Islamically prescribed.
But, he should instruct his brother to do these things in a kind and gentle manner, not with roughness and harshness, because there is no kindness in a thing but it adorns it, and there is no harshness in a thing but it makes it ugly.
If there is any element of harshness in his words, then the younger brother should advise him to be kind and gentle in his dealings with others and in his speech. There is nothing wrong with him asking his mother to tell him to do that, and if he needs to ask his father to do that after he comes back from his journey, then he may do that, by way of maintaining harmony within the family and avoiding division, and seeking to create an atmosphere of love and compassion among family members, and solving problems with mutual advice, wisdom and beautiful preaching, not with roughness, harshness and strictness.
And Allah knows best.