Zadhan said: I went to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), and people wearing silk and brocade had already taken their seats in his gathering before me. I said: "You have brought other people close and kept me at a distance?" He said: "Come closer." So he brought me close until he seated me on his own mat. Then he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Parents have a debt owed to them by their child. When the Day of Resurrection comes, they will both cling to him, and he will say: 'I am your child.' Then they will both wish, or (he said:) long, that it (the debt) had been even more than that."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10480