An Asura chieftain (Asurinda) (cp. Mtu.iii.138, 254). The Samyutta Nikāya (S.i.49f) says that on one occasion when he seized Candimā (Moon god), and on another Suriya (Sun god), both these invoked the aid of the Buddha. The Buddha then instructed Rāhu to let them free. Rāhu immediately let them go and ran to Vepacitti, "trembling and with stiffened hair." This incident evidently refers to the Indian myth of the eclipses, and the legend has been annexed by the Buddhists to illustrate the Buddha's power and pity.
Elsewhere (A.ii.17) Rāhu is spoken of as the chief of those possessing personality (attabhāva). The Commentaries (E.g., AA.ii.474; DA.ii.487f.; MA.ii.790; SA.i.86, contains more details and differs slightly) explain that he is four thousand eight hundred leagues in height, and that the breadth of his chest is one thousand two hundred yojanas. His hands and feet are two hundred leagues long, each finger joint measuring fifty leagues, the space between the eyebrows also measuring fifty leagues. His forehead is fifty leagues broad, and his head nine hundred leagues in height. His face measures one hundred leagues, his nose three hundred, and the depth of his mouth one hundred. He is jealous of the gods of the Sun and the Moon, and stands in their paths with wide open mouth. When they fall into his mouth, the gods abandon their abodes and flee for their lives. Sometimes he caresses their abodes with his hand only, or with the lower part of his jaw, or with his tongue. Sometimes he takes them up and places them against his cheek; but he cannot stop the course of either the Sun or the Moon; if he attempts to do so, he will meet with disaster. So he journeys along with them.
The seizure of the Moon by Rāhu and the escape from him is often used as a simile (E.g., Sn. vs. 465; J. i.183, 274; iii.364, 377; iv.330; v.453; DhA.iv.19, etc.). Rāhu is one of the four "stains" (upakkilesā) of the Sun and the Moon, preventing them from shining in all their glory (A.ii.53; Vin.ii.295; cp. J.iii.365). He is further mentioned as one of the five causes of lack of rain (vassassa antarāya). When he gathers water into his hands and spills it into the ocean, there is no rain (A.iii.243). The idea seems to be that he gathers up the rain water which is in the sky in order to cool his body.
To bring Rāhu down from the sky is mentioned as one of the impossible tasks (J.iii.477).
It is said (DA.i.285; MA.ii.790f ) that for a long time Rāhu did not visit the Buddha, he thought that being so tall he would fail to see the Buddha. One day, however, he decided to go, and the Buddha, aware of his intention, lay on a bed when he arrived, and, by his iddhi power, contrived to make himself so tall that Rāhu had to crane his neck to see his face. Rāhu, thereupon, confessed his folly and accepted the Buddha as his teacher.
Rāhu is mentioned (D.ii.259) as being among the Asuras who were present at the Mahāsmaya and as blessing that assembly. In this context he is called Rāhubhadda. When Rāhu steps into the ocean, the water of the deepest part reaches only to his knees (DA.ii.488). Rāhu is also called Veroca, and Bāli's hundred sons were called after him, he being their uncle (DA.ii.689). The name Rāhumukha is given to a form of torture (E.g., M.i.87; iii.164; Nid.154; Mil.197, 358), in which the victim's mouth is forced open by a stake and fire or spikes are sent through the orifice of the ear into the mouth, which becomes filled with blood (AA.i.293).