The core of the covenant relationship was, “You shall be My people, and I will be Your God.” (Jer. 30:22) And Jeremiah would lead into his famous account of the new covenant with the words of chapter 31. 31:1 reiterated the covenantal bond, and he spoke of “grace in the wilderness-” and rest (31:2). Both old and new were administrations of the covenant of grace. Furthermore, the name LORD, in English capitalized for Jehovah-the God of the covenant, had appeared to him and spoke. “Yes, I have loved you with an everlasting love; therefore with lovingkindness I have drawn you. (31:3) This is what it is to ‘know’ Him (9:24 cf. Ps. 36:10). To be without His “lovingkindness and mercies” (16:5), was to be without His peace.
It is to such lovingkindness that David appeals in Psalm 51. He asks for mercy based on the covenantal lovingkindness of the LORD. “According to the multitude of Your tender mercies, blot out my transgressions.” (v.1 cf. 16:5; 40:10-11; 69:16) ‘Lovingkindness’ was a common word used in the Psalms-17:7; 26:3; 36:7,10; 40:10-11; 42:8; 48:9; 51:1; 63:3; 69:16; 88:11; 89:33; 92:2; 103:4; 107:43; 119:88, 149, 159; 138:2; 143:8, and lovingkindnesses (25:6; 89:49). It is further explained as the source of salvation and deliverance (17:7), and the grounds of one’s trust (36:7). It accompanies those who ‘know’ Him (36:10).
It is found in the cluster of other covenantal terms such as righteousness, faithfulness, salvation, truth, and tender mercies (40:10-11; 69:16; 88:11; 92:2; 103:4; 138:2; ). It is “better than life” (63:3). Isaiah spoke of the mercy and lovingkindnesses of the LORD to His house (63:7). Finally, we find the wonderful expression of this covenantal bond in the prophet Hosea. “I will betroth you to me forever; yes, I will betroth you to Me in righteousness and justice, in lovingkindness and mercy; I will betroth you to Me in faithfulness, and you shall know the LORD.” (2:19-20)