Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 7 · Samskara Muhurtas
संस्कारमुहूर्ताः
शुद्धेऽष्टमे जन्मलग्नात्तयोर्लग्ने न नैधने ।शुभग्रहयुते दृष्टे पापदृष्टिविवर्जिते ॥ ३२३ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 323.
The 8th house should be clean. The rite's lagna (rising sign) should not be the 8th from the janma lagna (rising sign at birth). This holds for either of the two. Good planets should be in it or look at it. Bad planets should not look at it.
Simple meaning: Keep the 8th house clean, avoid the 8th from either parent's birth lagna, and let good planets support the rising sign.
शुभग्रहेषु धीधर्मकेंद्रेष्वरिभवे त्रिषु ।
Good planets in the 5th, 9th and corners, bad ones in the 3rd, 6th, 11th, and the Moon in a good house.
क्रूरग्रहाणामेकोपि लग्नादंत्यात्मजाष्टगः ।
A strong cruel planet in the 12th, 5th or 8th house can harm the mother or the child.
तस्मिञ्जन्ममुहूर्तेऽपि सूतकांतेपि वा शिशोः ।
The birth rite is done at the birth hour or when the birth impurity ends, after honouring the ancestors.