Therewith bless we God - We men do this; that is, all this is done by the tongue. The apostle does not mean that the same man does this, but that all this is done by the same organ - the tongue.
Even the Father - Who sustains to us the relation of a father. The point in the remark of the apostle is, the absurdity of employing the tongue in such contradictory uses as to bless one who has to us the relation of a father, and to curse any being, especially those who are made in his image. The word bless here is used in the sense of praise, thank, worship.
And therewith curse we men - That is, it is done by the same organ by which God is praised and honored.
Which are made after the similitude of God - After his image, Genesis 1:26-27. As we bless God, we ought with the same organ to bless those who are like him. There is an absurdity in cursing men who are thus made, like what there would be in both blessing and cursing the Creator himself.