I'll start with this one from Mohezhikuan by Zhiyi, translated by Swanson:
If there is no thought, that is the end of the matter. If there is even an ephemeral thought, this includes three thousand [realms]. But we cannot say that the single thought has prior existence, and that all phenomena (sarva-dharma) exist later, nor can we say that all phenomena have prior existence, and that the single thought exists later. For example, it is like a thing that changes through eight aspects [of arising, abiding, changing, and perishing]; it is not that things exist prior to these aspects and are caused to change through them, nor do the aspects exist prior to things and are caused to change through them [but things and their passing through arising, abiding, and so forth occur together]. There can be no priority nor posteriority [since it occurs simultaneously]. It is just that things are said to change by passing through these aspects, and these aspects are said to occur to things.
Thoughts are also like this. If all phenomena arise from a single thought, this is a horizontal [relationship]; if a thought in one moment encompasses all phenomena, this is a vertical [relationship]. But these are neither [merely] vertical nor [merely] horizontal. It is just that thought is all phenomena, and all phenomena is thought. Therefore [the relationship of thought and phenomena, the mind and objects] is neither [merely] vertical nor horizontal; they are neither the same nor different. This is mysterious and sublime, profound in the extreme, cannot be grasped conceptually, and cannot be verbalized. This is what is called [contemplating] “objects as inconceivable.” This is the meaning here [in terms of conventionality].