My heart was hot within me
Either with zeal for God; or rather with envy at the prosperity of wicked men, and with impatience at his own afflictions;
while I was musing the fire burned;
not the fire of the divine word, while he was meditating upon it, which caused his heart to burn within him; nor the fire of divine love, the coals whereof give a most vehement flame, when the love of God is shed abroad in the heart, and the thoughts of it are directed by the Spirit of God to dwell in meditation on it; but the fire of passion, anger, and resentment, while meditating on his own adversity, and the prosperity of others;
[then] spake I with my tongue;
and so broke the resolution he had made, ( Psalms 39:1 ) ; he spoke not for God, though to him; not by way of thankfulness for his grace and goodness to him, in supporting him under his exercises; but in a way of complaint, because of his afflictions; it was in prayer he spoke to God with his tongue, and it was unadvisedly with his lips, as follows.