瑜伽師地論 無尋唯伺地 · 無尋唯伺地：尋已伏、伺猶在的那一階——通往大梵的中間定
教理單元（定義型地）。地04 無尋唯伺地不另立本體——它的義理與地03 有尋有伺地「合說」（三地共一套五門）。本單元只做一件事：把它在「尋伺坐標」上的位置標清楚，再指回共同的本文。
論怎麼定義它
論在地03「界施設·數建立」裡，一句就把它定住了：
「即靜慮中間若定、若生，名無尋唯伺地。隨一有情，由修此故，得為大梵。」（本論）
「靜慮中間」，是初靜慮與第二靜慮之間的一段過渡定（中間靜慮）。修到這一段、或生在這一層的，便屬「無尋唯伺地」；而隨哪一有情修成此定，就能感得「大梵」（初禪天主）之身。
它在坐標上的位置
三地的分判，用的是同一把尺——「尋」與「伺」：尋是心裡粗的一層思量、伺是細的一層伺察。一路修定，這兩層次第靜下來：
- 有尋有伺地（欲界＋色界初靜慮）：尋、伺粗細俱在。
- 無尋唯伺地（靜慮中間）：粗的「尋」已伏，細的「伺」猶在——正是定心由粗轉細的「中間」一階。
- 無尋無伺地（第二靜慮以上至無色頂）：尋、伺俱歇。
無尋唯伺，就是這把尺上承先啟後的中段。
為何單立這一地
只伏了尋、還留著伺，看似只是一個過渡，論卻不肯把它併進前後任一地——因為尋伺的「分判」本身是修證的真實坐標，少了中間這一階，由粗到細的次第就斷了一節。它是一個真實的「教理坐標」，不是湊數的空檔。也要記得地03 已點明的總原則：三地之分，看的是「離尋伺欲」與否（斷沒斷那個貪根），不是看尋伺一時的現不現行——這一義通貫三地，於此一體承用。
指回共本文
無尋唯伺地的「界·相·如理作意·不如理作意·雜染」五門義理，與有尋有伺地合說，不另立、不重出——詳見 03-01 界施設 ～ 03-05 雜染。本單元只標其坐標位置；五門全幅，請於地03 共本文讀取。
A doctrine-pointer unit (a definition-type stage). Stage 04, the Stage with Sustained Thought Only, sets up no substance of its own — its doctrine is "expounded together with" Stage 03, the Stage with Both Applied and Sustained Thought (the three stages share one set of five gates). This unit does one thing only: it marks clearly this stage's position on the "applied-and-sustained-thought coordinate," then points back to the shared main text.
How the Treatise Defines It
In Stage 03, within the "Designation of Elements · Establishment by Number," the treatise fixes it in a single line:
「即靜慮中間若定、若生，名無尋唯伺地。隨一有情，由修此故，得為大梵。」 tr. "Just the intermediate of the dhyānas, whether as attainment or as birth, is called the Stage with Sustained Thought Only. Whatever sentient being, by cultivating this, comes to be the Great Brahmā." 〔the treatise〕
The "intermediate of the dhyānas" is that stretch of transitional attainment lying between the first dhyāna and the second dhyāna (the intermediate dhyāna). One who cultivates up to this stretch, or is born onto this level, belongs to the "Stage with Sustained Thought Only"; and whatever sentient being cultivates this attainment to completion comes to feel the reward of the body of the Great Brahmā (the lord of the first dhyāna heaven).
Its Position on the Coordinate
The threefold division of the stages uses one and the same measure — "applied thought" and "sustained thought": applied thought is the coarser layer of deliberation in the mind, sustained thought the finer layer of examination. As one cultivates concentration in course, these two layers grow still in sequence:
- The Stage with Both Applied and Sustained Thought (the desire realm plus the first dhyāna of the form realm): applied thought and sustained thought, coarse and fine, are both present.
- The Stage with Sustained Thought Only (the intermediate dhyāna): the coarse "applied thought" is already subdued, while the fine "sustained thought" yet remains — precisely the "intermediate" rung where the concentrated mind turns from coarse to fine.
- The Stage with Neither Applied nor Sustained Thought (from the second dhyāna up to the summit of the formless): applied thought and sustained thought are both at rest.
Sustained thought only, then, is the middle segment on this measure, taking up from what came before and opening onto what comes after.
Why This Stage Is Set Up on Its Own
To have subdued only applied thought while sustained thought still remains looks like a mere transition, yet the treatise will not fold it into either the stage before or the stage after — because the "division" of applied and sustained thought is itself the true coordinate of practice-realization: lacking this intermediate rung, the sequence from coarse to fine would break off a segment. It is a true "doctrinal coordinate," not a filler gap. We should also keep in mind the general principle Stage 03 has already pointed out: the division of the three stages looks to whether or not one has become free of the craving for applied and sustained thought (whether or not that root of craving has been cut), not to whether applied and sustained thought happen momentarily to be present in operation — this sense runs through all three stages and is here taken up whole.
Pointing Back to the Shared Main Text
The doctrine of the five gates of the Stage with Sustained Thought Only — element, characteristic, attention in accord with principle, attention contrary to principle, and defilement — is expounded together with the Stage with Both Applied and Sustained Thought; it is not set up separately, nor repeated — see in full 03-01 Designation of Elements through 03-05 Defilement. This unit only marks its position on the coordinate; for the full span of the five gates, read them in the shared main text of Stage 03.