All this, namely how the Grandsire, that illustrious one, acted as the charioteer on that occasion, had fully been known to Krishna beforehand.
कृष्णस्य चापि विदितं सर्वमेतत् पुरा ह्यभूत्॥ यथा पितामहो जज्ञे भगवान् सारथिस्तदा।