In plain words
Ignorance has no beginning and cannot be pinned down as this or that. It is called the first, causal adjunct. Discern the Self as other than the three bodies known as adjuncts, and itself free of every adjunct.
Word for word
They call beginningless ignorance, which cannot be described as precisely this, the primary [causal] adjunct. Discern the adjunct-free Self as distinct from the three bodies called adjuncts.