Mat 26:39 And he went a little further, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me: nevertheless not as I will, but as thou wilt.

In the Brit Hadasha / New Testament prayer proseuche g4335 and pray proseuchomai g4336 both appear.  Let us begin our exploration of these words with the places where Jesus / Yeshua used them in the gospel of Matthew.

Mat 17:21 Howbeit this kind goeth not out but by prayer and fasting.

Mat 21:13 And said unto them, It is written, My house shall be called the house of prayer; but ye have made it a den of thieves.

Mat 21:22 And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.

Professor Strong, in his concordance, tells us proseuche derives from proseuchomai .  It can mean: a prayer addressed to God or a place where people gathered for prayer (whether the synagogue or an open air place where no synagogue existed).  We see from the first example that battling demons requires this proseuche.  We see that the Temple of God existed for this word.  We see from the third example, God grants requests made in this manner.  Immediately we must ask ourselves, what then is to proseuchomai?

Professor Strong's concordance tells us the compound word proseuchomai g4336 contains inside it two other words: pro meaning toward and euchomai meaning God's imparted wishes.  Thus to pray requires an exchange of wishes of a person for the wishes of another: in this case God. Perhaps better said, we surrender our will in exchange for God's will. 

Consider the idea of surrendering human will for the will of God while reading the above quotes from Yeshua / Jesus.

Mat 17:21 tells us that the man who was possessed of many demons did not exchange his own will for the will of the Father, nor did this man keep the fast of Yom Kippur.  Yom Kippur is the time when even modern Jews focus on teshuva or a returning to God's will.

Mat 21:13 tells us the meaning of the temple of God, which is a place for people to return to the will of God.  Here they kept the feasts and rituals designed to free a person, their family, and their nation from sin.

Mat 21:22 tells us that whatever we ask for, that is in the will of God, we will receive. We must exchange our own desires for what he desires.

With this new understanding of prayer, we can see a deep and cutting strike made against the Pharisees when Yeshua chastises them in Matthew saying:

Mat 23:14 Woe unto you, scribes and Pharisees, hypocrites! for ye devour widows' houses, and for a pretence make long prayer: therefore ye shall receive the greater damnation.

The Torah requires the caring for of widows and orphans [Exodus 22:21]. By ignoring this necessity, these men demonstrated a refusal to exhange their will for God's will.  Even though the Pharisees stood out in the streets at the 3rd, 6th, and 9th hour Shucklen and reciting the Amida to their father, they defied the Law of Moses and lived according to their own will.  Thus Jesus / Yeshua also subtly reminded them of a "damnation" to come:

Exodus 22:22 Ye shall not afflict any widow, or fatherless child.  23 If thou afflict them in any wise, and they cry at all unto me, I will surely hear their cry;24 And my wrath shall wax hot, and I will kill you with the sword; and your wives shall be widows, and your children fatherless.