and, once made perfect, he became the source of eternal salvation for all who obey him
OJBAnd having been made shalem (complete), to all those with mishma'at toward Rebbe, Melech HaMoshiach, he became the source of Yeshu'at Eloheinu Olamim,
T4TBy becoming ◄all that God intended him to be/perfect►, he has now become fully qualified to be our Supreme Priest. As a result, he is the one who saves eternally all who obey him.