Jesus' speech was pure. No filthy word ever escaped His lips, and no idle word either. He always spoke the truth. There was no deceit in His mouth. No one could ever engage Jesus in a conversation about how to make more and more money (beyond one's needs). He was just not interested in such matters. His mind was set on things above and not on things on earth. No doubt, He used material things, but He did not love them, nor was He attached to any of them.
Jesus never belittled others or passed remarks or jokes about others that hurt them. He never made any subtle wounding statements. He never discussed the shortcomings of His disciples behind their backs. It is truly amazing that in three years, He never exposed Judas before the other eleven disciples - for even at the last supper, the eleven could not guess who was going to betray their Master.
Jesus used His tongue to encourage and admonish others, thereby making His tongue an instrument of life in God's Hand. He used His tongue to speak soothing words to the weary (Isa. 50:4), and also as a sword to cut down the proud and the haughty (Isa. 49:2).
How greatly encouraged the Roman centurion and the Syrophoenician woman must have felt when they heard Jesus praise them for their faith, publicly (Mt. 8:10; Mt. 15:28).
The sinful woman who was praised for her love (Lk. 7:47) and Mary of Bethany who was praised for her sacrificial offering (Mk. 14:6) would never have forgotten the words of Jesus.
How strengthened Peter must have been through Jesus' assurance that He would pray for him (Lk. 22:32). Just a few words, but what strength and encouragement they conveyed.
Many others must have heard words from Jesus' lips that lifted their weary spirits, for it says in Isaiah 50:4 that Jesus listened daily to His Father's voice so that He might have an appropriate word for the weary souls that came across His path each day.
He rebuked James and John for seeking places of honour and for wanting to take revenge on the Samaritans (Mt. 20:22,23; Lk. 9:55). And He rebuked His disciples seven times for their unbelief.
Jesus was never afraid of speaking the truth, even if it hurt others, for His heart was filled with love for them. He was not concerned whether His reputation for kindness would be lost by speaking strong words. He loved others more than Himself and so He was willing to sacrifice His reputation in order to help them. Therefore He spoke the truth firmly, lest men be ruined eternally. The eternal welfare of men mattered far more to Him than their opinions of Him.