Lifnei Iver for a chinuch-age child

Question

Is there a prohibition of lifnei iver (causing or being an accessory to someone else's sinning) for a child who has reached the age of chinuch (education to mitzvos, the point at which he/she should be taught to keep mitzvos)?

For example, can an adult give food to a non-religious 10 year old who won't be making a blessing on it (precluding all exterior factors which could make this not technically lifnei iver)?

I am looking for explicitly sourced answers, not extrapolations based on some other detail or understanding of how lifnei iver works.

Answer 1

The Gemara in Moed Katan 17a writes:

דאמתא דבי רבי חזיתיה לההוא גברא דהוה מחי לבנו גדול אמרה ליהוי ההוא גברא בשמתא דקעבר משום ולפני עור לא תתן מכשול דתניא ולפני עור לא תתן מכשול במכה לבנו גדול

The maidservant of Rebbi Yehuda HaNasi saw a man beating his mature son. She said: This man should be banned because he transgresses the prohibition of placing a stumbling block before the blind. For indeed we are taught in a Beraisa: You shall not place a stumbling block before the blind, this verse refers to a man who hits his mature son.

Thus, if a parent hits their child they are creating the potential for the child to strike back, which will result in that child violating an issur D'oraisa. Rashi there notes that although the child may rebel and sin, the responsibility lies with the parent. Ultimately, if the parent were to exercise more control, the child will not learn the art of retaliation and will gain greater respect for their parent. However, it is important to note, how old we deem a “בנו גדול” – “mature son”? The Shulchan Aruch, Yoreh Deah 240:20 brings this scenario down in halacha and the Rema says that this refers to a son aged 22 or 24 years old.

HOWEVER, (I note your point in the comments above), the Ritva goes one stage further. He notes that when the Gemara refers to a "בנו גדול" it is not necessarily a גדול, if a young child is of the disposition to respond in a similar fashion, then the issur extends to him as well. The only reason why the Gemara uses the term "gadol" there, is because it is more likely to happen with an older son.

ונראי' דברים דלא גדול גדול ממש אלא הכל לפי טבעו שיש לחוש שיתרם כנגדו בדבור או במעשיו כי אפי' לא יהא בר מצוה אין ראוי להביאו לידי מכה או מקלל אביו שלא ישתדלנו בדברים ומשום דאורחא דמילתא דבגדול שכיח כי הוא נקט גדול

(Parenthetically, Rav Shlomo Wolbe zt"l adds (see ספר זריעה ובנין בחינוך, 'ענישה', עמוד כה) that in this present day, if one even hits a three-year-old, the likelihood is that they will hit you back!)