 पुन्नाम्नो नरकाद् यस्मात् पितरं त्रायते सुतः।तस्मात् पुत्र इति प्रोक्तः पितॄन् यः पाति सर्वतः।। 
 Putra is so called as he delivers his father from a hell known as Put and protects the ancestors in all possible ways. 