Psalm 143:10

Teach me to do thy will
Revealed in the word; which saints desire a greater knowledge of in order to do it, and in which they delight; and also are desirous of being taught, and to practise submission to the will of God under afflictions; which was now the case of the psalmist;

for thou [art] my God;
his covenant God; and from whom all his afflictions came in a covenant way, and therefore desires to be instructed by him in them; see ( Jeremiah 31:18 ) ;

thy Spirit [is] good;
thy holy good Spirit, as the Targum; the Spirit of thy holiness, as the Arabic version: the Holy Spirit of God is meant, the third Person in the Trinity; who is "good" essentially, being of the same nature and essence with the Father and Son, with God, who is only good; and effectively is the author of the good work of grace upon the heart, and of the several particular graces there implanted, and who performs many good offices to the saints;

lead me into the land of uprightness;
or, "let thy good Spirit lead me into the land of uprightness" ^F26: either into a right land, as the Targum, where honesty prevails, and honest and upright men live; or, "through a plain way" ^F1, easy to be found, in which he should not err, and where would be no occasion of stumbling; or, "through the way of life", as the Syriac version; the way to eternal life, to heaven and happiness; the land where only truly righteous and upright persons dwell: such will be the new heavens and the new earth, as well as the ultimate state of glory, ( 2 Peter 3:13 ) ; and to this the Spirit of God is the leader and guide of his people, ( Psalms 48:14 ) .