Ādibrahmacariyaka-sīla: 'morality of genuine pure conduct', consists in right speech, right bodily action and right livelihood, forming the 3rd, 4th and 5th links of the 8-fold path see: sacca IV.3, 4, 5; cf. Vis.M I. In A. II, 86 it is said:
With regard to those moral states connected with and corresponding to the genuine pure conduct, he is morally strong, morally firm and trains himself in the moral rules taken up by himself. After overcoming the 3 mental chains ego-belief, skeptic doubt and attachment to mere rules and ritual; see: samyojana he becomes one who will be 'reborn 7 times at most' see: sotāpanna and after only seven times more wandering through this round of rebirths amongst men and divine beings, he will put an end to suffering.
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.