Commentary On Revelation by E.W. Bullinger
In the Epistle to the Assembly at Ephesus, the reference is to Exodus: to God's love in choosing them out of Egypt, and them making them a nation. See Hos. xi.1: |When Israel was a child, then I loved him, and called my son out of Egypt.| In Jer. ii.2 we see this |first love,| which Jehovah calls |the love of thine espousals.| And in Ezek. xvi. we have a full description of the workings and outcome of this |first love.| The whole of Ezek. xvi. must be read with Ex. xix.4-6. It is this |first love| which Israel is here charged with having |left.| This is the beginning of all the subsequent evil.