An eminent arahant, declared chief among monks skilled in creating forms by mind-power and in mental "evolution" (cittavivatta) (A.i.23). He was the younger son of the daughter of a rich merchant of Rājagaha, who developed intimacy with a slave and fled with him when her misconduct was discovered. She wished to return to her parents for the birth of her first child, but her husband always postponed the visit until, in the end, she started to go without his knowledge. He followed her, but the child was born by the wayside, and therefore they called him Panthaka. The same thing occurred at the birth of the second child, and he also received the name of Panthaka, he being Cūlapanthaka and his brother Mahāpanthaka. When the boys grew up they were taken to Rājagaha, where their grandparents took charge of them. Mahāpanthaka often accompanied his grandfather to hear the Buddha preach, and he yearned to become a monk. He easily obtained permission and entered the Order, in due course becoming an arahant. With the consent of his grandparents, he ordained Cūlapanthaka, but the latter proved to be a dullard, and in the course of four months was unable to learn a single stanza. It is said that in the time of Kassapa Buddha Cūlapanthaka was a clever monk, who once laughed to scorn a dull colleague who was trying to learn a passage by heart.
When Mahāpanthaka discovered his brother's stupidity, he asked him to leave the Order (see DhA.iv.190f), but Cūlapanthaka so loved the Buddha's teaching that he did not wish to return to the lay-life. One day Jīvaka Komārabhacca, wishing to give alms to the Buddha and the monks, asked Mahāpanthaka, who was acting as steward, to collect all the monks in the monastery. This he did, omitting only Cūlapanthaka who, he said, had made no progress in the Doctrine. Greatly grieved, Cūlapanthaka determined to leave the Order, but as he was going out the Buddha met him, took him into the Gandhakuti and comforted him, giving him a clean piece of cloth. "Sit with your face to the East," said the Buddha, "repeat the words 'rajoha-ranam' and wipe your face with the cloth." As Cūlapanthaka carried out these orders he noticed that the cloth became dirty, and as he concentrated his mind on the impermanence of all things, the Buddha sent a ray of light and exhorted him about the necessity of getting rid of the impurities of lust and other evils. At the end of the admonition Cūlapanthaka attained arahantship with the four patisambhidā, which included knowledge of all the Pitakas.
Tradition has it that Cūlapanthaka was once a king and that while going in procession round his city he wiped the sweat from his brow with a spotless garment which he wore and noticed how the cloth was stained. His mind then grasped the idea of impermanence, hence the ease with which he did so in his last birth.
Meanwhile, the Buddha and the monks were seated in Jīvaka's house, but when the meal was about to be served the Buddha ordered it to be stopped, saying that there were other monks left in the monastery. A servant was sent to find them, and Cūlapanthaka, aware of this, contrived that the whole grove appeared full of monks engaged in various activities. When the messenger reported this, he was told to discover which of the monks was Cūlapanthaka and to bring him. But all the monks answered to this name, and the messenger was forced to return without him. "Take by the hand the first who says that he is Cūlapanthaka," ordered the Buddha; and when this was done the other figures vanished. At the conclusion of the meal, Cūlapanthaka was asked to return thanks, and "like a young lion roaring defiance" the Elder ranged over the whole of the Pitakas in his sermon. Thenceforth his fame spread, and the Buddha, in order to prove how in previous births also Cūlapanthaka had profited by advice received, related to the monks the Cullakasetthi Jātaka (Thag.557-66; AA.i.119ff; J.i.114ff; DhA.i.239ff; ThagA.i.515ff; Vsm.388f).
The Dhammapada Commentary (i.250ff) gives another story of Cūlapanthaka's past. He went to Takkasilā to learn under a teacher, but though he did everything for his teacher he could learn nothing. The teacher, feeling sorry for him, taught him a charm: "Ghattesi ghattesi, kim kāranā ghattesi? āham pi tam jānāmi" ("You try and try; what are you trying for? I know it too"). When he had returned home thieves entered his house, but he woke up from his sleep and repeated the charm, whereupon the thieves fled, leaving behind them even their clothes. The king of Benares, wandering about the city in disguise, seeing what had happened, sent for Cūlapanthaka the next day and learnt from him the charm after paying him one thousand. Soon after-wards the king's commander-in-chief bribed the court barber to cut the king's throat, but while the barber was sharpening his razor the king repeated the charm. The barber, thinking that his intended crime was discovered, confessed his guilt. The king, realising that the youth had saved his life, appointed him commander-in-chief in place of the traitor, whom he banished. The youth was Cūlapanthaka and the teacher was the Bodhisatta.
Cūlapanthaka was a householder in the time of Padumuttara Buddha, and having seen a monk exalted by the Buddha to the rank of chief among those skilled in creating mind-born forms, aspired to the same position. In the time of Kassapa Buddha he was a monk and practised odātakasina for twenty thousand years (AA.i.119).
Cūlapanthaka was expert in rūpajjhāna and in samādhi, while his brother was skilled in arūpajjhāna and in vipassanā. When creating forms, other monks could produce only two or three, while Cūlapanthaka could bring into being as many as one thousand at the same time, no two being alike in appearance or action (ThagA.i.490; PsA.276).
According to the Apadāna (i.58f), Cūlapanthaka joined the Order at the age of eighteen. It is said (Vin.iv.54f) that when it was his turn to teach the nuns at Sāvatthi they expected no effective teaching, since he always repeated the same stanza. One day, at the end of the lesson, he overheard their remarks, and forthwith gave an exhibition of his magical powers and of his wide knowledge of the Buddha's teachings. The nuns listened with great admiration until after sunset, when they were unable to gain entrance to the city. The Buddha heard of this and warned Cūlapanthaka not to keep the nuns so late.
The Udāna (v.10; UdA.319f) contains a verse sung by the Buddha in praise of Cūlapanthaka, and the Milinda (p.368) quotes a stanza attributed to Cūlapanthaka which has so far not been traced elsewhere.