John Calvin Commentary Psalms 119:28

"My soul melteth for heaviness: Strengthen thou me according unto thy word." — Psalms 119:28 (ASV)

My soul drops away for grief. Previously, he said that his soul cleaved to the dust, so now, in almost the same manner, he complains that it melted away with grief. Some believe that he alludes to tears, as if he had said that his soul was dissolved in tears. But the simpler meaning is that his strength was poured out like water. The verb is in the future tense, yet it denotes a continued action.

The prophet assures himself of a remedy for his extreme sorrow, provided God stretches out His hand toward him. Formerly, when almost lifeless, he expected a revival through the grace of God; now also, by the same means, he cherishes the hope of being restored to renewed and complete vigor, even though he was nearly consumed.

He repeats the expression, according to Your word, because, apart from His word, God’s power would afford us little comfort. But when He comes to our aid, even if our courage and strength fail, His promise is abundantly efficacious to fortify us.