The Śūraṅgama Sūtra, Volume Ten: Empty and Clear False Thinking

Original text:即此所说。临高想心。能令汝形。真受酸涩。由因受生。能动色体。汝今现前。顺益违损。二现驱驰。名为虚明。第二妄想。

Explanation: The deluded thinking mind just described—imagining yourself standing at the edge of a cliff—can cause a genuine sour and astringent sensation to arise in the soles of your feet. Because of the arising of this inner feeling, it can bring about changes in the material body. For example, in the two phenomena just described, your mind feels that the sour object and the cliff are right before you, and thus changes appear in the body. When you now encounter favorable circumstances that benefit the body, a comfortable feeling arises; and when you encounter adverse conditions that harm the body, a painful feeling arises. These two phenomena are called the second false thought, "illusory clarity."

This says that the aggregate of feeling is a false thought of illusory clarity, and it is also an error of false thinking, so it is not real. If one clings to the aggregate of feeling, there will be the suffering of birth and death in saṃsāra, and one will not be liberated from afflictions.