不足为据 Insufficient as evidence
Explanation
不足为据的意思是：不够作为根据或证据。指某些言论、说法或证据不充分，不能作为判断是非或作出决定的依据。
The idiom "bù zú wéi jù" means: not enough to serve as a basis or evidence. It refers to statements, claims or evidence that are not sufficient to serve as a basis for judging right or wrong, or for making decisions.
Origin Story
话说唐朝时期，一位名叫李白的诗人，因得罪权贵被流放。一次，他流落到一个偏远的小村庄。村里有一位老农，听闻李白的大名，便将他请到家中做客。席间，老农滔滔不绝地讲述着自己如何凭借祖传的秘方种植出优质的稻谷，并以此发了家。李白听后，笑着说："老丈的经验固然宝贵，但仅凭这些不足为据，无法断定将来是否还能持续丰收。农业生产受多种因素影响，气候变化，虫害等等，都可能影响收成。"老农听后沉默良久，最终点了点头，表示理解。
During the Tang Dynasty of ancient China, a poet named Li Bai, offended dignitaries and was exiled. Once, he ended up in a remote village. An old farmer in the village, having heard of Li Bai’s reputation, invited him home as a guest. During the banquet, the old farmer talked at length about how he had used an ancestral secret recipe to grow high-quality rice, and thus became rich. Li Bai listened, and said with a smile, "Old man, your experience is certainly valuable, but just this is not enough to be evidence, it can not be determined whether or not it can continue to have a good harvest. Agricultural production is affected by many factors, climatic changes, pests and so on, all can affect the harvest. " The old farmer listened and was silent for a long time, finally nodding in agreement.
Usage
该成语主要用于说明某种证据、说法或理由不足以作为判断或决定的依据。常用于书面语，也可以用于口语。
This idiom is mainly used to explain that certain evidence, statements or reasons are insufficient to serve as the basis for judgment or decision. It is often used in written language but can also be used in spoken language.
Examples
-
他的证词不足为据，不能作为定案的依据。
tā de zhèngcí bù zú wéi jù, bù néng zuòwéi dìng'àn de yījù
His testimony is insufficient as evidence and cannot be used as a basis for a final decision.
-
仅凭几句传闻不足为据，我们需要进一步调查取证。
jǐn píng jǐ jù chuánwén bù zú wéi jù, wǒmen xūyào jìnbù diàochá qǔzhèng
Relying solely on hearsay is insufficient; we need to conduct further investigations and gather evidence.