I assume you refer to hymns #150 and #401. The former was written by Josiah Condor c.1836.  Mr Darby said of it that it was the hymn he most wished he had written.  #401 is an adaptation of it that was published in the 1903 edition of the Little Flock hymn-book, probably by its editor, T. H. Reynolds.  Others may be able to add more about that.  Both versions are now in the public domain.