A large number of Devas of Tranquil Mind (Samacittā) come to the Buddha at Jetavana and ask him if he will visit Sāriputta, who is preaching at the Migāramātupāsāda on the person who is fettered both inwardly and outwardly. The Buddha agrees in silence and appears at the Migāramātupāsāda. Sāriputta greets the Buddha and salutes him. The Buddha relates to him the visit of the Devas and tells him that a large number of them can stand in a space not greater than the point of a gimlet, and that, too, without crowding each other. This is because they have trained themselves to be tranquil in the senses and in the mind. Such tranquillity leads to tranquillity also of body, speech, and thought. Followers of other schools do not know this teaching (A.i.64f).
In the discourse of Sāriputta, (A.i.62f) referred to by the Devas, the Elder explains that the monk who keeps the Pātimokkha restraints is proficient in the practice of right conduct, seeing danger in the slightest faults such a one is reborn among the Devas and is therefore a "Returner." Thus he is fettered inwardly to the self. Others there are who are born in Deva worlds and there become anāgāmīs. These are fettered outwardly. Yet others are proficient in revulsion, in the ending of sensuality, of any existence and become anāgāmīs.
It is said (AA.i.320; cf. SNA., p.174; Mil. p.20) that at the conclusion of this sutta, as at the conclusion of the Mahāsamaya, Mangala, and Cūla Rāhulovāda Suttas, one hundred thousand crores attained arahantship.
The sutta was preached by Mahinda on the evening of his arrival in Ceylon. After his interview with Devānampiyatissa, Mahinda asked Sumana sāmanera to announce the preaching of the Dhamma. This announcement was heard throughout the Island, and gradually the news of it spread to Brahmā's heaven. There was then an assembly of Devas, just as on the occasion of Sāriputta's preaching of the sutta. Mhv.xiv.34ff.