A great study.
Murray indirectly refutes Anselm's dictum, "God is compassionate, in terms of our experience, because we experience the effect of compassion. God is not compassionate, in terms of his own being, because he does not experience the feeling (affectus) of compassion." No, says, Murray, “God, the Father, loves his enemies and it is because he loves his enemies that he makes his sun rise upon them and sends them rain. This is just saying that the kindness bestowed in sunshine and rain is the expression of divine love, that back of the bestowal there is an attitude on the part of God, called love, which constrains him to bestow these tokens of his lovingkindness. This informs us that the gifts bestowed by God are not simply gifts which have the effect of good and blessing to those who are the recipients but that they are also a manifestation or expression of lovingkindness and goodness in the heart or will of God with reference to those who are the recipients. The enjoyment on the part of the recipients has its ground as well as its source in this lovingkindness of which the gifts enjoyed are the expression. In other words these are gifts and are enjoyed because there is in a true and high sense benevolence in the heart of God... We are hereby given a disclosure of goodness in the heart of God and of the relation there is between gifts bestowed and the lovingkindness from which they flow.”
And this love and goodwill toward the unbelieving and reprobate is not incidental to God's nature, but is central:
“[Matthew 5:48] means that what has been adduced by way of divine example in the preceding verses is set forth as epitomizing the divine perfection and as providing the great exemplar by which the believer’s attitude and conduct are to be governed and the goal to which thought and life are to be oriented. The love and beneficence of God to the evil and unjust epitomize the norm of human perfection. It is obvious that this love and beneficence on the part of God are regarded by our Lord himself as not something incidental in God but as that which constitutes an element in the sum of divine perfection.”