MIDRASH TEHILLIM
1.....(18.7)
And he said, Erchamcha (I love You), O LORD, my strength.
A.
In the Aramaic version this reads Rachamit (I love) You O LORD, my strength. RCHM in Aramaic clerly means to love, for in the Aramaic Targum the term love in: "And you shall love the Lord..." (Devarim - Deuteronomy 6:5) is also rendered RCHM.
ERCHAMCHA may also be understood as - I call You compassionate (rachum) and gracious.
Or, I fill You with compassion (Rachamim) for Your creatures
Or, I make You loved by Your creatures.
B.
Rabbi Nehemiah said in the name of Rabbi Simeon son of Lachish, David wished to use a single word which would include all the following meanings, such as - rock, fortress, deliverer, and so the Holy Spirit told David, use the word - STRENGTH.