Ten metaphors for emptiness

Ten metaphors for emptiness (S. upamāna; C. shíyù 十喩). A set of ten metaphors that illustrate how phenomena are empty of inherent existence and yet still appear.

The ten metaphors are:

1. A magical illusion (S. māyā; T. sgyu ma; C. 幻喩); like a magic illusion, things are made to appear due to the temporary coming together of causes and conditions
2. A mirage (S. marīci; T. smig rgyu; C. 焰喩): like a mirage, things appear, but they are not real
3. A reflection of the moon in water (S. udakacandra; T. chu zla; C. 水中月喩): like a reflection, things appear, but have no reality of their own
4. Space (S. ākāśa; C. 虛空喩)
5. An echo (S. pratiśabda; T. brag cha; C. 響喩): like an echo, things can be perceived, but there is nothing there, either inside or outside
6. A city of gandharvas (S. gandharvanagara; T. dri za'i grong khyer; C. 犍闥婆城喩): like a city of gandharvas, there is neither a dwelling nor anyone to dwell
7. A dream (S. svapna; T. rmi lam; C. 夢喩): like a dream, objects perceived with the five senses are not there, but they appear through delusion
8. A shadow (chāyā / pratibhāsa; C. 影喩)
9. A reflection (bimba) in a mirror (ādarśa) (pratibimba 鏡中像喩)
10. a magical transformation (S. nirmita; C. 化喩)

These metaphors are discussed in detail in the Dazhidu lun.