(Thy Lord hath not forsaken thee) your Lord has not left you since He inspired you (nor doth He hate thee) since He loved you; this is the reason for Allah's oath, this was revealed after the revelations from Allah stopped for 15 nights because the Prophet (pbuh) forgot to say " if Allah wills " when he promised the idolaters to answer their questions. And because the revelations stopped for this period of time the idolaters said: the Lord of Prophet has forsaken him and He hates him.