The meaning of this sentence is as follows: that confession and admission, says God, is on my part an admission of thy wish, being manifestly full of unadulterated joy; and your faith is not doubtful, but without any hesitation it has a share of modest awe and reverence; therefore that which thou hast received before, as to be done unto thee on account of thy faith in me, shall certainly be done; for this is what is meant by yes.
Why does he say, But I will set up my covenant with Isaac, whom Sarah shall bring forth about this time in the succeeding year? (Genesis 17:21).