Islam has made much recommendation in this matter
1- We find, in the will of Amirul Mo-mineen (a.s.) for his sons Hasan and Husain (a.s.) when the accursed Ibne Muljim and attacked the Amir: For Gods sake, for Gods sake, behave nicely with your neighbours because it is one of the recommendations of your Prophet (s.a.w.s.). He had made so much admonition regarding good behaviour with neighbours that we imagined that very soon they neighbours will be made entitled to inheritance.
2- Imam Sadiq (a.s.) has said: You have to behave nicely with your neighbours because Allah has commanded it.
3- Imam Sadiq (a.s.) said: Good behaviour with neighbours increases prosperity.
4- Imam Baqir (a.s.) is reported to have said that he read in the book of Ali (a.s.) that the Holy Prophet (s.a.w.s.) had in his letter to Muhajirs and Ansaars written: A neighbour is like a man himself who is neither to be harmed nor sinned and moreover giving respect to the neighbour is like giving respect to one mother.
5- Abi Rabi quoted the Imam Sadiq (a.s.): Once when his house was full of visitors he said: Remember that, in fact, one who is not a good neighbour is not from us.
6- If one grabs wrongly a little measure of his neighbours land, will be garlanded by Allah with the weight of seven layers of earth until he meets the Almighty unless he repents and withdraws his misdeed.
7- And also said: The one usurps the right of his neighbour will no be allowed the fragrance of paradise and his place will be hell which is a bad abode indeed.
8- And also said: The one usurps the right of his neighbour is not from us. Jibraeel (a.s.) continuously recommended about the rights of the neighbour until I imagined that he will also inherit the dead.
9- The Holy Prophet (s.a.w.s.) said: There are three categories of the neighbours: the first group has three rights: the right of Islam, the right of neighbourhood and the right of kindness. The second group has two rights: The right of Islam and the right of neighbourhood. The third group has one right: and it is the right by way of being neighbour. They are all Kafirs who live side by side with the Muslims!
10- Abu Baseer says: I heard from Imam Sadiq (a.s.): If one refrains from harassing his neighbour, God ignores his faults on the Day of Judgement.
11- The Holy Prophet (s.a.w.s.) said: If one harasses his neighbour due to greed of his house, God hands over the house of such harasser to his neighbour.
12- Imam Sadiq (a.s.) said: He is far away from the Mercy of Allah, he is far away from the Mercy of Allah who gives harassment to hid neighbour.
The problem of neighbourhood is an important problem about which Islam has given much recommendation. Yet, in spite of all this, we Muslims sometimes do not pay attention to it and harass one-another by loud talks, troublesome horns, climbing terraces, throwing dirty water etc in front of the neighbours' houses
It is also possible that our neighbour may be in need of some necessities of life. In such circumstances too we should not lag behind but must try our best to live sympathetically side-by-side. And this right is applicable not only to a Muslim neighbour but it applies to non-Muslim neighbours also.
Hence Imam Sadiq (a.s.) says: Even if your are sitting by the side of a Jew make a nice kind of sitting.
And perhaps it can be said: The wording is common which makes no difference between big and small. Environment. Wherever and whenever it is called neighbour it applies in these traditions. It is difficult to believe that it is obligatory.