redeem = deliver. Hebrew. padah, See notes on Exo_6:6; Exo_13:13.
mercies' = mercy's, or lovingkindness.
To the chief Musician. See App-64. Written by Hezekiah for his special circumstances; but on account of verses: Psa_44:1-8 was handed over for general use at the Feast of the Passover. See note below.
upon = relating to, or concerning.
Shoshannim = Lilies. Put by Figure of speech Metalepsis for "Spring", and "Spring" put for the great spring festival, the Passover. See App-65.