John Gill Commentary Psalms 119:76

"Let, I pray thee, thy lovingkindness be for my comfort, According to thy word unto thy servant." — Psalms 119:76 (ASV)

Let, I pray you, your merciful kindness be for my comfort ,
&c.] Shown in the provision and promise of a Saviour; in the forgiveness of sins through him; a discovery and application of which yields comfort under afflictions;

according to your word to servant ;
a word of promise, in which he had assured him of his love, grace, mercy, and kindness; and that he would continue it to him, and comfort him with it: to make such a promise, and show such favour, was an instance of condescending grace to him, who was but his servant, and unworthy of his regard.