Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
त्रितयं ज्ञांशकाद्युग्मममिश्रैः सममादिशेत् ।लग्ने चापांत्यभागस्थे तदंशस्थबलिग्रहैः ॥ ५७ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 57.
Then say three are born. From Mercury's navamsha (one-ninth part of a sign), a pair; with unmixed planets, say alike. The lagna (rising sign) may be in the last part of Sagittarius. Strong planets may stand in that navamsha. (Our text is unclear here: the words after 'three' do not settle.)
Simple meaning: Mercury's sight can give three at one birth. A lagna late in Sagittarius begins a rule for many.
वीर्याढ्यज्ञार्किसदृष्टैः कोशस्थावहवोगिनः ।
Strong Mercury and Saturn can give many in one birth. The ten womb months each have a planet lord.
मासानां तत्समं वाच्यं गर्भस्थस्य शुभाशुभम् ।
Each month of pregnancy goes well or badly by its lord. Mercury in a luck house can bring a deformed child.
आरार्की चेज्यभांशस्थौ सदंतोगर्भकस्तदा ।
Some planet places can give a child born with teeth, hunchbacked or lame.