But by this is meant wickedness, which is established in the souls of foolish men; the remedy for which (as one seeks for remedies for a severe disease) is found to be the just man, who is in possession of the panacea, justice. When, therefore, he has repelled these evils he is filled with joy, as also is Sarah; for she says, "The Lord hath caused me laughter;" and she adds further, "so that whosoever hears it shall rejoice with me." Genesis xxi. 6.

For God is the author of virtuous laughter and joy; so that we must look upon Isaac not as the offspring of creation, but as the work of the uncreate God. For if Isaac, being interpreted, means laughter, and if it be God who is the cause of laughter according to the true testimony of Sarah, then he may be most properly said to be the father of Isaac. And he also gives a share to Abraham of his own proper appellation, to whom, when he eradicated pain from wisdom, he gave rejoicing as an offspring.