that day. The interpretation here is of the day of Babylon's overthrow. The application is of the yet future Great Tribulation of Mat 24. This is in contrast with the day of Restoration.
great, &c. = too great to have another like it.
Jacob's. Not Israel's, for it is the natural seed that is here in question, not the spiritual. See notes on Gen_32:28; Gen_43:6; Gen_45:26, Gen_45:28.