In larger context:
Isa 47:8 Therefore hear now this, thou that art given to pleasures, that dwellest carelessly, that sayest in thine heart, I am, and none else beside me; I shall not sit as a widow, neither shall I know the loss of children:
Isa 47:9 But these two things shall come to thee in a moment in one day, the loss of children, and widowhood: they shall come upon thee in their perfection for the multitude of thy sorceries, and for the great abundance of thine enchantments.
Isa 47:10 For thou hast trusted in thy wickedness: thou hast said, None seeth me. Thy wisdom and thy knowledge, it hath perverted thee; and thou hast said in thine heart, I am, and none else beside me.
Isa 47:11 Therefore shall evil come upon thee; thou shalt not know from whence it riseth: and mischief shall fall upon thee; thou shalt not be able to put it off: and desolation shall come upon thee suddenly, which thou shalt not know.
Isa 47:12 Stand now with thine enchantments, and with the multitude of thy sorceries, wherein thou hast laboured from thy youth; if so be thou shalt be able to profit, if so be thou mayest prevail.
Isa 47:13 Thou art wearied in the multitude of thy counsels. Let now the astrologers, the stargazers, the monthly prognosticators, stand up, and save thee from these things that shall come upon thee.
Isa 47:14 Behold, they shall be as stubble; the fire shall burn them; they shall not deliver themselves from the power of the flame: there shall not be a coal to warm at, nor fire to sit before it.
Isa 47:15 Thus shall they be unto thee with whom thou hast laboured, even thy merchants, from thy youth: they shall wander every one to his quarter; none shall save thee.
that sayest in thine heart, I am, and none else besides me: sole monarch of the world, empress of the whole universe; no competitor with me, none that can rival me. These words are sometimes used by the eternal and unchangeable Jehovah of himself, and indeed they suit with none but him; and it is the height of insolence and blasphemy in a creature to use them of itself; they fitly express that sovereignty, supremacy, infallibility, and even deity, which mystical Babylon assumes and ascribes to her head:
and thou hast said in thine heart, I am, and none else besides me; none so wise and knowing as myself. This is what the oracle said of the Chaldeans (n),
“the Chaldeans and the Hebrews are the only wise.”
This is repeated, to observe the haughty and insolent boasts of themselves.
As for a sample of God’s Sovereignty check my earlier post on Psalm 106.