Jesus' teachings are best understood in their historical, cultural, and geographical context. The superficial analogies that are drawn in the Zen Teachings of Jesus are an ad hoc theory imposed on rather than derived from the teachings of Jesus. It is similar to how some astrologist writers seek to put an astrological spin on the gospels to siphon off some of the star power of Jesus. It's religious parasitism.

Jesus adhered to the Hebrew religion and comfortably stayed within that tradition. His emphasis on 'silent' prayer, was simply in contradistinction to the hypocritical performative prayer of certain religious leaders that did not come from pure motives. The reason why prayer was silent, was not because it was in any way meant to be a mystical eastern style meditative experience leading to some kind of emotional ecstasy or zen or any other psychological manifestation, but rather because it was meant to emphasise the true goal of prayer i.e. maintaining a personal relationship with God through verbal communication.

Believers were encouraged to approach God like they would a friend or father and speak to him about their lives and not consider their human needs too lowly to concern a deity. Eastern meditation on the other hand is characterised by emptying of the mind, the polar opposite of how Jesus taught his disciples to pray. Jews and Christians throughout history have believed that on the other end of a prayer is a personal God who is responsive to our petitions whereas buddhism has no concept of a personal God but instead concerns itself merely with the human mind. For Jews and Christians the efficacy or power is not in the act of praying, but in the voluntary act of God. For Zen buddhists the efficacy or power is inherent in the act of meditation.

Communal prayer was still considered appropriate and was encouraged, Jesus just didn't want anyone showing off to their religious friends as a means to gain status without truly caring about God, His righteousness, etc.

Prayer by itself was also not considered a method to discover truth. There is a heavy emphasis on seeking truth in the study of the word of God which runs throughout Jesus' teachings, which was already present in Judaism and continues to this day in Christianity. The desert fathers, as well as mystical sects in judaism and islam are outliers, and their religious practices are amalgamations of mystical traditions of other religions with their respective host religion (christianity, islam, judaism). Theirs is a religious phenomenology that draws on the religious verbiage and concepts of a familiar religion, without concerning itself with the authoritative source of said religion, but rather with seeking a mystical experience.

It is not just literalists and evangelicals that consider eastern style meditation and associated religious concepts as foreign to mainstream historical christianity and judaism, it's most reputable scholars in the fields of NT studies, Church History, etc.

* the personal relationship with G'd in silent prayer is nonverbal. G'd knows all things, is part of all things, it makes no sense to tell G'd anything. hence: *silent* prayer. It __does___ make sense to listen though , with your heart. And in the gentle *felt* presence your wounds may heal, and your love may grow. why *felt* presence? because G'd is everywhere, where else would G'd be. so you don't pray for G'ds presence. you pray to immerse into it.

* this immersion is not about fancy mystical experiences, but about healing in the presence of what as Christians we call G'd; it often is initially calm, then happy, ecstatic to some, and then that makes room for neither ecstasy nor void but pure presence, a state that can be experienced, but not described appropriately. On that path there lays and lurks inner work on your personal baggage, a liberating cleansing process, which is not only fun while it lasts, and a process which contemplative teachers today could call 'purifications'. The beatifications of the sermon on the mount give a fairly good step by step guidance of this purification process which leads to life "in Christo", as Paul describes it.

* contemplative or silent prayer was and is an outlier, yes, however certainly not in early Christianity, see the sibling comment for a random quick example https://news.ycombinator.com/item?id=26497034

* contemplative / silent prayer, like comparable Jewish and Islamic traditions, and like a number of eastern traditions, puts the experiential personal liberation above authoritative teachings of some church or another. It's a radical shift of authority from rulebooks and logical learning to an inner process, guided and supported by open minded teachers.

* I respectfully doubt you have read the book. It is anything but superficial.

May I ask if you have personal experience with any kind of meditation, secular (like MBSR) or in some religious tradition?

There's not a good deal of solid literature on it in English that I've found, but contemplative Christian prayer evolved later on. I want to say circa 500 or so. I think today it's primarily found in the Eastern Orthodox churches.

here is a random paper from 1994, back when peer review was still a thing:

https://www.jstor.org/stable/3270411?seq=1

it connects silent prayer to Philo, a contemporary of Jesus https://en.wikipedia.org/wiki/Philo

and it connects silent prayer to early desert fathers, like Clement of Alexandria https://en.wikipedia.org/wiki/Clement_of_Alexandria

Unfortunately I don't have access to that paper, and the timeline isn't in the abstract. The abstract mentions it took a long time to be accepted.

Also. For clarity (you may know this, but others may not) I want to distinguish very clearly the difference between a silent prayer and meditation.

A silent prayer is verbalized intention within your head, sometimes mouthed. If you were to look up Judaism's silent prayer, it is repeating a ritual sequence of words - the meanings of which you should know. As traditionally conceived, it is addressing the Eternal as a Person.

The different meditation approaches I've encountered - conventional "Western mindfulness" and a more intense secular Hindu system - are focused on detaching awareness. Sometimes mantras are used/repeated. It is exceptionally variant from the early silent prayer approach, or even the nominal silent prayer approach of today.

Contemplative prayer did start with the desert fathers, I think.