Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 7 · Samskara Muhurtas
संस्कारमुहूर्ताः
नोत्कटे भूषिते नैव याने न नवमेऽहि च ।क्षौरकर्म महीपानां पञ्चमेपंचमेऽहनि ॥ ३४१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 341.
Not when puffed up, not when dressed up, not on a journey, and not on the 9th day. Kings should be shaved every 5th day.
Simple meaning: Do not shave when decked out, on a journey or on the 9th day. Kings shave every 5th day.
कर्तव्यं क्षौरनक्षत्रेऽप्यथ वास्योदये शुभम् ।
Shave on a good star or lagna. It is also allowed at a king's order, a sacrifice or a death.
उद्वाहेऽखिलवारर्क्षतिथिषु क्षौरमिष्टदम् ।
At a wedding shaving is allowed on any day. In lucky rites the razor is offered first.
नवमे सप्तमे वापि पञ्चमे दिवसेऽपि वा ।
Choose the 9th, 7th, 5th or 3rd day before the rite, a good star, weekday and lagna.