As Elder Paisios said, "Speechless be the lips of impious who refuse to reverence thy revered icon..." (from the Paraclesis) refers to those who refuse to properly kiss the icons when they venerate them!
I'd like to add this( also from Elder Paisios) to what Julia posted above...
Elder,in the Supplication Service of the Theotokos,why does a verse in the hymns of praise say,
Speechless be the lips of the impious who do not venerate your sacred Icon?
When someone is not devout and yet kisses the Icons,are his lips not speechless?
And,when the devout kisses the Icons,aren't his lips full of praise?
There are some people who do not even touch the Icon when they venerate it.
Others touch only their lips to the Icon when they kiss it Here,like this(Without a sound)
Did you hear anything?
No.
Well then,"speechless are the lips.
Whereas the devout person kisses the Icon and you can hear the sound of the kiss.
In that case,the lips are "eloquent" with praise.
It is not a matter of cursing when the verse says"speechless",but rather that those lips are without a sound,while the others are eloquent with sounds.
When we look upon the holy Icons,our hearts should be overflowing with love for God and for the Saints,and we should prostrate ourselves to venerate the Icons and kiss them devoutly.
Your body is the temple of the Holy Spirit.
You see every divine service begins and ends with the veneration of the Holy Icons.
If people could understand this they would feel such joy,they would receive so much power!
The Foundation is devoutness.
You see,someone may lean against the wall where an Icon has stood and he receives Grace,while
another may own the best Icon,but because he is not devout,receives no benefit.
Or one may benefit from a simple wooden cross,while another,who is not devout,may not even benefit from the True Precious Cross itself
Cultivate your devoutness and your modesty as much as you can.
This will help you receive the Grace of God.
For,if someone is devout and spiritually modest and humble too,he can expect to receive divine
Grace.
If he has no devoutness and no humility,the Grace of God does not come to him.
What does the Sacred Scripture say?
But to this man will I look,even to him that is poor and of a contrite spirit,
and trembleth at My word. ISA 66;2.
Elder Paisios-"Spiritual Awakening"