Ibn Abbas (ra) asked, “Is your mother still alive?”
He said, “No.”
So Ibn Abbas (ra) told him, “Repent to Allah and do your best to draw close to Him.”
Then Ataa’ ibn Yasaar (ra) who over heard their conversation asked, “why did you ask him if his mother was still alive?”
Ibn Abbas (ra) said, “Because I know of no other deed that brings people closer to Allah than kind treatment and respect towards one’s mother.”
[ Bukhari, Al-Adab al-Mufrad, 1/45 baab birr al-umm.]