Have mercy upon me, O Jehovah! The Psalmist again betakes himself to the mercy of God. The word chnn, chanan, which I have rendered have mercy, is substantially the same as to gratify, to do a pleasure. It is as if he had said, I bring no merit of my own, but humbly pray for deliverance solely on the ground of thy mercy. When he speaks of crying daily, it is a proof of his hope and confidence, of which we have spoken a little before. By the word cry, as I have already had occasion frequently to remark, is denoted vehemence and earnestness of soul. The saints do not indeed always pray with a loud voice; but their secret sighs and groanings resound and echo upwards, and, ascending from their hearts, penetrate even into heaven. The inspired suppliant not only represents himself as crying, but as persevering in doing so, to teach us that he was not discouraged at the first or second encounter, but continued in prayer with untiring earnestness. In the following verse, he expresses more definitely the end for which he besought God to be merciful to him, which was, that his sorrow might be removed. In the second clause, he declares that there was no hypocrisy in his crying; for he lifted up his soul to God, which is the chief characteristic of right prayer.

Be merciful unto me, O Lord - It was mercy after all that he relied on, and not justice. It was not because he had any claim on the ground that he was "holy," but all that he had and hoped for was to be traced to the mercy of God.
For I cry unto thee daily - Margin, as in Hebrew, "All the day." The meaning is, that he did this constantly, or without intermission.

Be merciful unto me - I have no merit; I plead none, but trust in thee alone.
I cry unto thee daily - My state deeply affects me; and I incessantly cry for thy salvation.

Be merciful unto me, O Lord: for I (c) cry unto thee daily.
(c) Which was a fair token that he believed that God would deliver him.

Be merciful unto me, O Lord,.... In my distressed and miserable condition, being an object of mercy, pity, and compassion; this petition is used by Christ in Psalm 41:10.
for I cry unto thee daily; or "all the day"; every day, and several times in a day, Psalm 55:17 constant and importunate prayer is the duty of saints, and available with God, 1-Thessalonians 5:17. Christ was much in the exercise of it, Luke 6:12.