This, the second petition of the litany, addresses God the Son; and as we make it, we echo the words of the many who petitioned Christ whilst he walked amongst us – such as the Cannanite woman who cried out “Have mercy on me, O Lord, Son of David”, and the father of one demon-possessed who knelt to plead “Lord, have mercy on my son” (Matthew 9:27, 15:22, 17:15). Like them, we come to God the Son in faith and plead for his mercy: yet to us also belongs that blessed confidence of knowing that He has already redeemed us to belong to him (Galatians 3:12; Isaiah 62:12). Indeed when we call upon God the Son for mercy, we are calling on one who in unfathomable mercy gave his life for us (John 3:16), miserable sinners (1 Timothy 1:15).
Biblically, the mercy of the Son is bound up with that of the Father; the Apostle Paul joins them both in his epistles, writing in one place “Grace, mercy, and peace from God the Father and Christ Jesus our Lord” (II Timothy 1:2), and in another praying for Onesiphorus saying “may the Lord grant him to find mercy from the Lord on that Day” (II Timothy 1:18).