The ninth book of the Aṅguttara Nikāya, the Collection of the Numbered Discourses of the Buddha, collects 432 suttas or discourses whose subject matter is centered on groups of nine topics. This time, however, the nine objects do not appear as explicitly as in previous volumes. 
This book revolves fundamentally around the nine spheres or dimensions: the four jhānas, the four āyatanas and the state of cessation, through a multiplicity of variations of varying complexity that reaches its climax in AN 9.41. With the householder Tapussa, a dense, complex and especially complicated discourse to reconstruct that describes in depth the direct mystical path to full enlightenment. 
The most interesting suttas, in addition to the above are: 
AN 9.5. Powers: The best way to care is to encourage, settle and ground the faithless in faith, the unethical in ethics, the greedy in generosity and the ignorant in wisdom. 
AN 9.19. A Deity: "Practice the jhānas, bhikkhus! Do not be negligent! Do not repent later, like those ancient devas." 
AN 9.22. A Wild Colt. Another sutta employing the taming of horses, so akin to the Buddha. 
AN 9.33. The nine progressive contemplative attainments: A description of contemplative practice. 
AN 9.37. By Ānanda: On how not to experience the sensory field. 
AN 9.71. Emotional sterility: On the consequences of doubts about the Master. 
This book does not contain false suttas. 
In short, this time the arduous and exhaustive work of research and reconstruction in comparative linguistics has been especially difficult and the result is priceless for those of you who want to embark on the direct route to Nibbāna.