Martanda (Vaivasvata) begot another son who was gifted with great intelligence and was called Manu. Yama was his younger brother.
मार्तण्डस्य मनु/मानजायत सुतः प्रभुः। यमश्चापि सुतो जज्ञे ख्यातस्तस्यानुजः प्रभुः॥