Commentary on the Bible, by Adam Clarke, , at sacred-texts.com
The psalmist praises the Lord for his mercies to himself, Psa 138:1-3. He foretells that the kings of the earth shall worship him, Psa 138:4, Psa 138:5. God's condescension to the humble, Psa 138:6. The psalmist's confidence, Psa 138:7, Psa 138:8.
The Hebrew and all the Versions attribute this Psalm to David, and it is supposed to have been made by him when, delivered from all his enemies, he was firmly seated on the throne of Israel. As the Septuagint and Arabic prefix also the names of Haggai and Zechariah, it is probable that it was used by the Jews as a form of thanksgiving for their deliverance from all their enemies, and their ultimate settlement in their own land, after Ahasuerus, supposed by Calmet to be Darius Hystaspes, had married Esther, before which time they were not peaceably settled in their own country.
I will praise thee with my whole heart - I have received the highest favors from thee, and my whole soul should acknowledge my obligation to thy mercy. The Versions and several MSS. add יהוה Yehovah, "I will praise thee, O Lord," etc.
Before the gods will I sing - נגד אלהים neged Elohim, "in the presence of Elohim;" most probably meaning before the ark, where were the sacred symbols of the Supreme Being. The Chaldee has, before the judges. The Vulgate, before the angels. So the Septuagint, Ethiopic, Arabic, and Anglo-Saxon. The Syriac, Before kings will I sing unto thee. This place has been alleged by the Roman Catholics as a proof that the holy angels, who are present in the assemblies of God's people, take their prayers and praises, and present them before God. There is nothing like this in the text; for supposing, which is not granted, that the word elohim here signifies angels, the praises are not presented to them, nor are they requested to present them before God; it is simply said, Before elohim will I sing praise unto Thee. Nor could there be need of any intermediate agents, when it was well known that God himself was present in the sanctuary, sitting between the cherubim. Therefore this opinion is wholly without support from this place.
For thy loving-kindness - Thy tender mercy shown to me; and for the fulfillment of thy truth - the promises thou hast made.
Thou hast magnified thy word above all thy name - All the Versions read this sentence thus: "For thou hast magnified above all the name of thy holiness," or, "thy holy name." Thou hast proved that thou hast all power in heaven and in earth, and that thou art true in all thy words. And by giving the word of prophecy, and fulfilling those words, thou hast magnified thy holy name above all things - thou hast proved thyself to be ineffably great. The original is the following: כי הגדלת על כל שמך אמרתך ki higdalta al col shimcha, imrathecha, which I think might be thus translated: "For thou hast magnified thy name and thy word over all," or, "on every occasion." Kennicott reads, "He preferred faithfulness to his promise to the attribute of his power." I believe my own translation to be nearest the truth. There may be some corruption in this clause.
With strength in my soul - Thou hast endued my soul with many graces, blessings, and heavenly qualities.
All the kings of the earth - Of the land: all the neighboring nations, seeing what is done for us, and looking in vain to find that any human agency was employed in the work, will immediately see that it was thy hand; and consequently, by confessing that it was thou, will give praise to thy name.
They shall sing in the ways of the Lord - They shall admire thy conduct, and the wondrous workings of thy providence, if they should not even unite with thy people.
Though the Lord be high - Infinitely great as God is, he regards even the lowest and most inconsiderable part of his creation; but the humble and afflicted man attracts his notice particularly.
But the proud he knoweth afar off - He beholds them at a distance, and has them in utter derision.
Though I walk in the midst of trouble - I have had such experience of thy mercy, that let me fall into whatsoever trouble I may, yet I will trust in thee. Thou wilt quicken me, though I were ready to die; and thou wilt deliver me from the wrath of my enemies.
The Lord will perfect - Whatever is farther necessary to be done, he will do it.
Forsake not the works of thine own hands - My body - my soul; thy work begun in my soul; thy work in behalf of Israel; thy work in the evangelization of the world; thy work in the salvation of mankind. Thou wilt not forsake these.