Jamieson, Fausset and Brown on Ephesians 6:4

4. fathers--including mothers; the fathers are specified as being the fountains of domestic authority. Fathers are more prone to passion in relation to their children than mothers, whose fault is rather over-indulgence.

provoke not--irritate not, by vexatious commands, unreasonable blame, and uncertain temper [Alford]. Col 3:21, "lest they be discouraged."

nurture--Greek, "discipline," namely, training by chastening in act where needed (Job 5:17; He 12:7).

admonition--training by words (De 6:7; "catechise," Pr 22:6, Margin), whether of encouragement, or remonstrance, or reproof, according as is required [Trench]. Contrast 1Sa 3:13, Margin.

of the Lord--such as the Lord approves, and by His Spirit dictates.