What did the Prophet Muhammad (saw) mean when he said 'A neighbor is more entitled to receive the care of his neighbor'?
      Narrated 'Amr bin Ash-Sharid:                          Al-Miswar bin Makhrama came and put his hand on my shoulder and I      accompanied him to Sa'd. Abu Rafi' said to Al-Miswar, "Won't you order     this (i.e. Sa'd) to buy my house which is in my yard?" Sa'd said, "I      will not offer more than four hundred in installments over a fixed      period." Abu Rafi said, "I was offered five hundred cash but I      refused. Had I not heard the Prophet saying, 'A neighbor is more      entitled to receive the care of his neighbor,' I would not have sold      it to you." The narrator said, to Sufyan: Ma'mar did not say so.      Sufyan said, "But he did say so to me." Some people said, "If someone      wants to sell a house and deprived somebody of the right of      preemption, he has the right to play a trick to render the preemption      invalid. And that is by giving the house to the buyer as a present and     marking its boundaries and giving it to him. The buyer then gives the      seller one-thousand Dirham as compensation in which case the preemptor     loses his right of preemption."