I hear the objection: ‘If the Prayer of the Heart is that important, vital, radically vital, how come Jesus never talked about it?’
Well He talked about it plenty of times, the most obvious one being: “dwell in Me as I dwell in you” (John 15).
But before addressing today’s point, let us remember that “of entering the Kingdom” of God is a fairly common indication on the movement itself of the Prayer of the Heart. Entering the Kingdom is in fact entering into God’s area, God’s domain, where He acts in a sovereign way; in a word it is to enter intoJesus’ being (Jesus is the Furnace of Love), to be under the influence of the Holy Spirit.
Jesus makes the conditions to enter of entering into the Kingdom: “If you do not become like children you can’t enter into the Kingdom”. God is like a child [pure, simple,…], and if we want to enter within Him, we need to become like Him, by choosing to trust Him, totally, without any conditions: and also we need to entrust ourselves (The best way to love is to give everything and give oneself).
In this post, I would like to point out one of the most beautiful, yet discreet, descriptions of the Prayer of the Heart (Matthew 11:28-30): 
”Come to Me, all you who are weary and burdened, and I will give you rest. Take my yoke upon you and learn from me, for I am gentle and humble in heart, and you will find rest for your souls, for my yoke is easy and my burden is light.” Let us read it with its own oral swinging rhythm:

“- Come to Me,

all you who are weary and burdened,

and I will give you rest.
Take my yoke upon you
and learn from me,
for I am gentle and humble in heart,

and you will find for your souls rest,
for my yoke is easy
 
and my burden is light.”
– “come to me” is the key expression that shows us what we have to do in order to do the Prayer of the heart, in order to be introduced into Jesus-Furnace-of-Love. Or at least it indicates the first part of what we have to do. In fact we need to use our free will (by choosing to give ourselves to Jesus), otherwise God/Jesus will not force Himself into us.
First we need to get rid of our yoke: i.e. all that we are carrying, the idols we have, the other gods in whom we trust, our worries, concerns, difficulties, problems…, we need to give all that to Jesus: He removes them, He takes away the weight from us, so we become free and able to move and fly… we can be in Hishands… under the Action of the Holy Spirit.
– “weary and burdened”: Jesus describes our inner state when we are not dwelling in him: we are ‘weary and burdened’. Our yoke is our worries and burdens. Instead of carrying our actual Yoke, we are invited to take His one. In fact, we are not invited to remain yokeless…

The Yoke is seen as well in the Jewish Biblical and Talmudic exegesis as the symbol of  Marriage. Husband and wife will carry the same yoke, they will be married (tie the knot) and they will be bound to the same yoke.
Please have a look at a yoke (see below), how it is built and its purpose: it is a piece of wood made for two animals, and its purpose is to keep them tightly linked in their movement and journey. Where one goes, the other will go.
Jesus wants us to dwell in Him, constantly, wherever we go. He wants us to be where He is. In fact he says:  “that you also may be where I am” (John 14:3). Here is the entire sentence: “My Father’s house [Jesus himself (see John 2)] has many rooms; if that were not so, would I have told you that I am going there to prepare a place for you? And if I go and prepare a place for you, I will come back and take you to be with me that you also may be where I am.” (John 14:2-3)
This is achieved by taking His Yoke. The purpose of the Yoke is to be where He is.
Burdens make us heavy, distance us very far from God…
– “take my Yoke”: This is the second indication Jesus gives us in order to achieve the Prayer of the Heart: “take my Yoke”. By offering ourselves to Him, and wanting to do all that He wants, with no restrictions… something will happen: we will be introduced into Him, we will receive REST or, if you prefer, TRUE PEACE… an overflowing of the Holy Spirit.
This is why Saint Antony the Great, Father of all Monks, says in one of his letters that the Yoke of Christ is the Holy Spirit…  being tightened by Jesus’ Yoke, we then constantly receive His Holy Spirit.
Let us see now on the following diagram how it works:
Jesus’ goal is to welcome us into the Sun (Himself). Our heart is initially heavy and weary, carrying burdens, carrying another yoke: our heart is sinking in the water of our being, sensations, emotions, imagination, thoughts.
Where is Jesus? Is He like the Sun high up, waiting for us to fly to Him? No, God became incarnate, and Jesus is at the door of our being (at the surface of the water/sea), knocking at the door of our free will inviting us to give Him our yokes and receive His.
By making this act of trust, by entrusting, surrendering, abandoning ourselves into His Hands, being tied to Him, He then takes us and introduces us into His being (the sun in the drawing), so that we receive Peace, we receive the action of the constant outpouring of the Holy Spirit.

Here is the key: “come to me” means: come to the surface of the water, rise above yourself in order to love, and give me yourself. This is key to the success of the Prayer of the Heart and the only way Jesus will be able to take us and lift us (“He took-with-Him […] and went-up” (Matthew 17:1)). Jesus won’t force us, so he awaits for us to love Him: give ourselves to Him. “take my yoke” means: allow me to take you, believe in the Power of my Holy Spirit, capable to take you and lift you, introduce you into the depth of My Heart.

Conclusion: there is something that Jesus offers. He knows where we are (immersed in the water, under the weight of our yokes); He comes to us (He doesn’t await us high up in the sun, where He normally is);He comes to us and offers to free us from our burdens, yokes, tiredness, and offers us a lightweight, HisYoke, the Action of the Holy Spirit, that takes us, with its power, and puts us in Him.
Let us experience His Action, how it makes our life lighter and easier, putting speed and power into our relationship with God, easing our prayer, easing our daily life.
Why delay taking up His Yoke.
Some people might say: well His Yoke is His Cross… and it is heavy. Well this is an erroneous understanding of His Cross, because Jesus’ Cross is the centre of the manifestation of the all-powerfultransformative action of God, action that lifts us – Crucified Christ is the only ‘place’ where evil is transformed into a superior Good… the power that lifts the World…
Here again, with a correct understanding of the Power that flows from Jesus on the Cross, we experience that amazing uplifting power that transforms our life into His.