Great is the Lord, and greatly to be praised - See Psalm 96:4, note; Psalm 18:3, note.

And his greatness is unsearchable - See Job 5:9, note; Job 9:10, note; Job 11:7-8, notes.

Psalm 145:3 Parallel Commentaries

Exhortations to those who are Called
IF, after searching you find that you are effectually called, I have three exhortations to you. 1. Admire and adore God's free grace in calling you -- that God should pass over so many, that He should pass by the wise and noble, and that the lot of free grace should fall upon you! That He should take you out of a state of vassalage, from grinding the devil's mill, and should set you above the princes of the earth, and call you to inherit the throne of glory! Fall upon your knees, break forth into …
Thomas Watson—A Divine Cordial

Covenant Duties.
It is here proposed to show, that every incumbent duty ought, in suitable circumstances, to be engaged to in the exercise of Covenanting. The law and covenant of God are co-extensive; and what is enjoined in the one is confirmed in the other. The proposals of that Covenant include its promises and its duties. The former are made and fulfilled by its glorious Originator; the latter are enjoined and obligatory on man. The duties of that Covenant are God's law; and the demands of the law are all made …
John Cunningham—The Ordinance of Covenanting

The Mercy of God
The next attribute is God's goodness or mercy. Mercy is the result and effect of God's goodness. Psa 33:5. So then this is the next attribute, God's goodness or mercy. The most learned of the heathens thought they gave their god Jupiter two golden characters when they styled him good and great. Both these meet in God, goodness and greatness, majesty and mercy. God is essentially good in himself and relatively good to us. They are both put together in Psa 119:98. Thou art good, and doest good.' This …
Thomas Watson—A Body of Divinity