Upright, or sincere, to wit, in performing what thou hast promised to such persons, this being a great part or act of sincerity, when one's deeds and words, or professions, agree together; as, on the contrary, for those that deal hypocritically and wickedly with thee, thou wilt make them to know thy breach of promise, as it is expressed, Numbers 14:34. The sense of the verse is, Thou metest to every one the same measure which he meteth out to others, and givest to him the fruit of his own doings, and therefore thou wilt perform mercy and truth to those who are merciful and true to others, as through thy mercy I have been.
Related Commentaries of Psalms 18:25
Psalms 18:25
25 With the merciful thou wilt shew thyself merciful; with an upright man thou wilt shew thyself upright;