The Gemara in Masechet Rosh Hashanah (23A) emphasizes the importance of sharing one's Torah knowledge with others. A person who studies but does not share his knowledge, the Gemara remarks, is comparable to a fragrant Hadas tree planted in a desert, where nobody can enjoy its scent. One who has studied Torah and accumulated knowledge must teach what he has learnt rather than keep his scholarship to himself.
The question was posed to Rabbi Yitzchak Weiss (Romania-England-Israel, 1902-1989) as to whether one should teach advanced Torah material to weak students, who might misinterpret the Halacha. Even if students are imbued with Yir'at Shamayim (fear of Heaven) and are seriously committed to Halacha, if they have limited background or skills they may not necessarily be able to reach the correct conclusions after hearing a Shiur. They are likely to misunderstand their Rabbi and reach incorrect conclusions on Halachic matters. Should a Rabbi refuse to teach students of a lower caliber due to this concern?
Rabbi Weiss responded (Minchat Yitzchak 9:101) that a Rabbi must be prepared to teach all students, even those of a lower caliber, provided that they are sincerely God-fearing. The Rabbi should make every effort to present the material in a clear manner so as to avoid misunderstanding, rather than refuse to teach weaker students. Given the importance of sharing one's Torah knowledge, a scholar must be willing to teach students of all levels, and endeavor to convey the information in a clear and intelligible manner.