כִּסְאֲךָ אֱלֹהִים, עוֹלָם וָעֶד
The Jewish Greek translation which came to be called the Septuagint renders this verse this way: 'Your throne, God, is forever and ever.' So also Aquila, Theodotion, and Symmachus--second century Jewish translators.
According to this translation, the king who is addressed in the preceding verses is addressed as 'God' here. Abraham Cohen in The Soncino Books of the Bible states that 'this appears to be the obvious translation but does not suit the context.'
Saadya Gaon, Ibn Ezra, and Rashi depart from this reading, but each of them translate this passage differently. 'God will establish your throne' (Gaon). 'Your throne is the throne of God' (Ibn Ezra). Rashi, who reads this psalm allegorically, understands אֱלֹהִים as a vocative like the Septuagint, but he takes it as an address to the Torah scholar, and he renders אֱלֹהִים as 'judge' (as he and Onkelos do at Exodus 7:1 and elsewhere): 'Your throne, O judge.'
Prior to Rashi, the Targum also understands אֱלֹהִים as a vocative, but to insure that it might not be understood as an address to the king of Israel in the sense of 'God', it reads כּוּרְסֵי יְקָרָךְ יְיָ קַיָים לְעָלְמֵי עַלְמִין ('The throne of your glory, Yeya, lasts forever and ever'). See also the Alshich.
Are there any translators or commentators who translate אֱלֹהִים in Psalm 45:7a as a vocative addressed to the king in the sense of 'God' as do Aquila and Theodotion?