(69) The proud have forged a lie against me: but I will keep thy precepts with my whole heart.
(70) Their heart is as fat as grease; but I delight in thy law.
Similar to verse 51 ("The proud have had me greatly in derision: yet have I not declined from thy law."), it is another reminder to keep God's commandments no matter what others say or do.
(71) It is good for me that I have been afflicted; that I might learn thy statutes.
Afflicted - OT:6031`anah (aw-naw'); a primitive root [possibly rather ident. with OT:6030 through the idea of looking down or browbeating]; to depress literally or figuratively, transitive or intransitive (in various applications, as follows):
We don't care for affliction much - the idea of looking down, brow beating, depressed . . . but God does not send those experiences our way fruitlessly: "My brethren, count it all joy when ye fall into divers temptations; Knowing this, that the trying of your faith worketh patience. But let patience have her perfect work, that ye may be perfect and entire, wanting nothing." (James 1:2-4) - And not only so, but we glory in tribulations also: knowing that tribulation worketh patience; And patience, experience; and experience, hope: And hope maketh not ashamed; because the love of God is shed abroad in our hearts by the Holy Ghost which is given unto us." (Romans 5:3-5)
What is our response to tribulation and testings? Do we see them as good and able to work good in our lives? ("And we know that all things work together for good to them that love God, to them who are the called according to his purpose." Romans 8:28) My response determines whether or not the affliction will draw me closer to God and help me to learn His statutes, or whether I will refuse.