Benefits of Kindness to Parents
 فَقَالَ أَبُو عَبْدِ اللٌّهِ )ع): يَا مُيَسِّرُ قَدْ حَضَرَ أَجْلُكَ غَيْرُ مَرَّةٍ وَ لاَ مَرَّتَينِ كُلُّ ذٌلِكَ يُۆَخِّرُ اللٌّهُ أَجَلَكَ لِصِلَّتِكَ قُرَابَتِكَ وَ إِنْ كُنْتَ تُرِيدُ أَنْ يُزَادَ فِي عُمْرِكَ فَبِرْ شَيْخَيكَ يَعْنِي أَبَوَيهِ
 Hanan Ibn Sudair narrates: “We were in the presence of Imam Sadiq (A.S) and amidst us was Muyassir. During the discussion, the topic of silah rahim (establishing bonds of kinship with one’s relatives) came to the fore, whereupon] the Imam (peace be upon him), [addressing Muyassir], said: ‘O’ Muyassir! On several occasions, your end had drawn near, but on each occasion, Allah delayed your death due to your acts of silah rahim with your relatives. If you desire to have your life-span increased, exhibit goodness and kindness towards your parents.’” 
Biharul Anwar, Volume 74, Page 84
  
  Other links: 
 Looking at Parents 
 Attachment to Parents 
 The Most Exalted Station