Charles Ellicott Commentary Psalms 77:10

"And I said, This is my infirmity; [But I will remember] the years of the right hand of the Most High." — Psalms 77:10 (ASV)

And I said ... —The word rendered “infirmity” may, by derivation, mean “wounding” or “piercing.” So Symmachus, “my wound;” Aquila, “my sickness.” Gesenius says, “that which makes my sickness.”

If we adhere to this meaning, we must understand it as mental sickness or “madness.” Consequently, we would interpret the poet as saying that to indulge in despairing cries is mere madness (compare King Lear’s, “Oh! that way madness lies”). He will then recall God’s ancient deliverances and so re-establish his faith.

But it seems more natural to adopt a meaning that the related verb very commonly has (Leviticus 19:8; Ezekiel 36:22; Psalms 74:7; Psalms 89:39), and translate it as: “I said this (such despair) is on my part profanation, profanation of the years of the right hand of the Most High.” To despair of continued help from One who had been so gracious in the past is a kind of blasphemy. The word “profanation” must be understood as repeated for the sake of the grammar.