तस्मै स होवाच ।द्वे विद्ये वेदितव्ये इति ह स्म यद्ब्रह्मविदो वदन्ति परा चैवापरा च ॥ ४ ॥
Śaunaka asks for the one thing whose knowing is the knowing of everything, and is answered with a distinction between two kinds of knowledge.The lower is drawn as a list because it is one and can be completed; the higher cannot be enumerated and is drawn as a single centre. The asymmetry between the two sides is the mantra's point, not a shortage of items.
In plain words
Aṅgiras said to him: ‘Two Vidyās are to be known—so the knowers of Brahman declare: Parā and Aparā.’