A man and his wife, householders of Sumsumāragiri in the Bhagga-country. When the Buddha visited the village and stayed at Bhesakalāvana, they went to see him. They immediately fell at his feet, calling him "son" and asking why he had been so long away. It is said that they had been the Bodhisatta's parents for five hundred births and his near relations for many more. The Buddha preached to them and they became sotāpannas. The Buddha visited their village once more when they were old. They entertained him, telling of their devotion to each other in this life and asking for a teaching which should keep them likewise together in after-life. The Buddha referred to this in the assembly of the Sangha, declaring them to be the most intimate companions (vissāsikā) among his disciples. (A.I.26, A.II.61f, AA.i.216f, 246; ii.514; SA.ii.182)
Once, when Nakulapitā lay grievously ill, his wife noticed that he was fretful with anxiety. She assured him there was no need for anxiety on his part, either on behalf of her or his children. She spoke with such conviction that Nakulapitā regained his composure of mind and grew well. Later he visited the Buddha and told him of this, and was congratulated by the Buddha on having such an excellent wife. (A.III.295ff)
The Samayutta Nikaya (S.3.1, S.4.116; A.IV.268) contains records of conversations between Nakulapitā and the Buddha. Both husband and wife are mentioned in lists of eminent disciples. (A.iii.465; A.iv.348).
It is said that' Nakulapitā's desire for eminence was first conceived in the time of Padamuttara Buddha. He was then a householder of Hamsavati, and was present at an assembly where the Buddha declared someone to be chief of the vissāsikas. A.I.216.
The first chapter of the Khandha Samyutta. S.3.1-21.
Nakulapitā visits the Buddha at Bhesakalāvana and asks for a teaching to comfort him since he is now old and always ailing. The Buddha advises him to train his mind. Nakulapitā, then visits Sāiriputta and asks him to explain the Buddha's teaching on this point. Sāiputta explains in detail that training of the mind implies the getting rid of thoughts of self with regard to the khandhas. S.iii.1 ff.
Nakulapitā visits the Buddha at Bhesakalāvana and asks him why some beings are wholly set free in this very life, while others are not. This has to do with grasping, says the Buddha, and then proceeds to explain it. S. iv. 107, 116.