Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Calendar, Muhurta Elements
कालमानं मुहूर्ताङ्गानि च
परीता विपरीता वा विष्टिर्नेष्टा तु मंगले ।मुखे पंचगले चैका वक्षस्येकादश स्मृतः ॥ २२१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 221.
Vishti (bad half of a moon day), whether taken direct or reversed, is not wanted in a good act. Five ghatikas (24-minute unit) are in the mouth, one in the throat, eleven in the chest.
Simple meaning: Vishti is not wanted in a good act. Its parts are the mouth, throat and chest.
नाभौ चतस्रः षट् कट्यां तिस्रः पुच्छाख्यनाडिकाः ।
In Vishti, the mouth part may spoil work, the throat part risks life and the chest part poverty.
कट्यामुन्मत्तता नाभौ च्युतिः पुच्छे ध्रुवं जयः ।
In Vishti, the waist part may disturb the mind, the navel may bring a fall, the tail sure victory.
दिवामुहूर्ता रुद्राहिमित्रपितृवसूदकम् ।
The fifteen parts of the day each have a god as lord. The list starts here.