On this solemn gesture and signification, see Eze_20:5. Here it is an oath added to a threat, to make it more dreadful to them, and to make it successful in keeping them from the sin threatened.
That I would scatter them; foretold them of a captivity which should come upon them for their sins, which it is probable was often inculcated in their hearing before Moses penned it for them, Deu_32:15 -42 Le 26:31-33, and it is ingeminated to make it pierce the deeper, and affect them the more.