Barbour Collection of Connecticut Vital Records (Guilford VR 2:56) Since there is not a vital record for the birth of either Daniel or Abigail, there is no proof it was these two who married. However in the book Families of Early Guilford, Connecticut, FHL 974.67 G1 D2t, p. 597 Abigail the daughter of Stephen and Sarah Pierson Hand married Daniel Bradley, obviously the right couple.
In the article "Nathaniel Porter of Farmington and Bethlehem, Connecticut, by Bryson C. Cook and Janet S. Porter, pub. NEHGS 2009, the staff at NEHGS provided to following documentation for Daniel Bradley and this marriage: Talcott, Families of Early Guilford [note 11], 117-18, 121; Ralph D. Smyth, “The Bradleys of New Haven and Guilford (Conn.),” Register 57 (1903):134-41 at 136-37, 141; Smyth, “Joseph Hand of East Guilford” [note 12], Register 55:32.