Samyutta Nikaya. Connected Discourses of the Buddha. Part III. Book of Aggregates

Samyutta Nikaya, or "Connected Discourses of the Buddha", is the third of the four major collections of the Sutta Pitaka of the Pali Canon. It consists of 52 chapters (samyuttas), distributed across 5 books, or parts. Each chapter has a... unique theme to which various discourses (suttas) are attached, hence the name of this collection.
The third part, known in Pali as Khanda Vagga, is almost entirely devoted to examining the doctrinal category of "aggregates", through which the Buddha discusses sensory existence as such. This model helps to better understand and classify the experiences encountered, and such understanding is important for a deeper grasp of the Four Noble Truths, especially the first, the truth of suffering.