How long should burial of the deceased be delayed when waiting for his relatives?
Question

                Is it permissible to delay burying the deceased until some of his relatives come from other cities, at their request?
Praise be to Allah.
      It is not permissible to delay (burial) except within the 
      limits of what is needed to prepare him or to wait for his relatives or 
      neighbours to come, if that will not take too long according to local 
      custom, because the Prophet  (peace and blessings of Allaah be upon 
      him) said: “Hasten to bury your dead….” This hadeeth was narrated by 
      Maalik and Ahmad, 2/240; and by al-Bukhaari, 2/87-88. It is not permitted 
      to hold a “wake” for him, or to set up pavilions (for mourners to gather), 
      i.e., so called mourning rituals. Those who could not attend the funeral 
      may pray over his grave, if he was in the city where he was, within a 
      period of two months, because the Prophet  (peace and blessings of 
      Allaah be upon him) prayed over the grave of Umm Sa’d one month after her 
      burial.