According to Ish Upanishad, what needs to be rejected is the attachment (moha) and the grief (shoka), as these two emotions drive us to cling tenaciously to this manifested world. Attachment and grief are the two impediments in the path of vidya. Detachment helps overcome grief; this leads to happiness, which is essential for understanding the unmanifested reality. A seeker attached to any object, any person or any principle, can never understand vidya, the knowledge of the unmanifested.
