Did worse than all - before him - Omri was,

1. An idolater in principle;

2. An idolater in practice;

3. He led the people to idolatry by precept and example; and, which was that in which he did worse than all before him,

4. He made statutes in favor of idolatry, and obliged the people by law to commit it. See Micah 6:16, where this seems to be intended: For the statutes of Omri are kept, and all the works of the house of Ahab.

above

1 Kings 16:25,31,33 But Omri worked evil in the eyes of the LORD, and did worse than all that were before him...

1 Kings 14:9 But have done evil above all that were before you: for you have gone and made you other gods, and molten images, to provoke me to anger...

1 Kings 21:25 But there was none like to Ahab, which did sell himself to work wickedness in the sight of the LORD, whom Jezebel his wife stirred up.

2 Kings 3:2 And he worked evil in the sight of the LORD; but not like his father, and like his mother...

Whether a Vow Consists in a Mere Purpose of the Will?
Objection 1: It would seem that a vow consists in nothing but a purpose of the will. According to some [*William of Auxerre, Sum. Aur. III, xxviii, qu. 1; Albertus Magnus, Sent. iv, D, 38], "a vow is a conception of a good purpose after a firm deliberation of the mind, whereby a man binds himself before God to do or not to do a certain thing." But the conception of a good purpose and so forth, may consist in a mere movement of the will. Therefore a vow consists in a mere purpose of the will. Objection …
Saint Thomas Aquinas—Summa Theologica