This is a Royal Psalm. Royal Psalms are so called because they are about the king or are pronounced by the king. The Royal Psalms sang of hopes for future deliverance and conditions of salvation to be ushered in by an anointed one of God. Psalm 72 hopes and prays that this coming anointed one will rule from sea to sea, and from the river to the ends of the earth (Ps 72,8). Then verse Ps 72,17 says: “may men bless themselves by him, all nations call him blessed!” Clearly the name of this coming king is to be used in blessings, and in this sense he will be a paradigm of blessing. But the entire context seems to say more than this. The verse Ps 72,1 begins with a prayer to God to endow this king with God’s own justice and righteousness. As a result uprightness shall flourish and peace will be established (Ps 72,7), he will be the source of life and vitality (Ps 72,6), and all kings will pay homage to him and all nations will serve him (Ps 72,11). All this is because he redeems the poor from oppression and violence (Ps 72,12.14). The context thus says, Yahweh’s anointed king in Zion will be the source of blessing of peace, justice and fullness of life for all nations and in this way be an agent of the blessing of Abraham.
 Cf. M. E. Tate, Psalms 51-100, WBC, Vol. 20, Word Books Publishers, Texas, (1990), 225.