As liquefied iron, poured (into a mould), takes the form of the mould, so is the entrance of the Individual Soul into the foetus.
यथा लोहस्य नि:स्यन्दो निषिक्तो बिम्बविग्रहम्। उपैति तद् विजानीहि गर्भे जीवप्रवेशनम्॥