Shemot 21:15 lists striking one’s parent as a capital offense, and the gemara[1] says that this applies when he causes a chabura (wound). The gemara then asks whether one may perform a bloodletting (a medical procedure at that time) on his parent. It brings two derivations from the Torah to show that when the action is done in a positive context, it is permitted. Yet, the gemara relates that Amora’im would not allow their sons to perform certain procedures, fearing that they might accidentally make a wound, which is a serious transgression. Regarding someone other than a parent, where the sin of injuring is much less severe, it is permitted to draw blood despite the concern of injury. The gemara’s conclusion seems to be that although one should have been permitted to perform medical procedures that include piercing his parent’s body, we instruct him to refrain. The Shulchan Aruch[2] rules unequivocally that a child should not perform a bloodletting on or remove a splinter from a parent. However, the Rama,[3] based on the Rambam, adds that if the child is the only one available to do the procedure and the parent needs it, he should do so.
Let us apply this general halachic background to our specific case. Several poskim discuss injections for parents, including four responsa that appear in the beginning of Gesher HaChayim, vol. II. We will summarize the main indicators for leniency and try to arrive at a conclusion.
The Gesher HaChayim[4] raises the point that, by its halachic definition, a chabura always includes blood that is spilled or that accumulates under the skin. The gemara’s conclusion, which was meant only as a stringency,[5] expresses concern about the possibility of a mistake. However, perhaps it was intended for a case of a definite wound, with the mistake being that the procedure went beyond the therapeutic need. Thus, if there is only a small chance of a wound at all, it is possible that the stringency does not apply (The probability of blood, of course, depends upon the site of the injection, among other factors).
The Minchat Chinuch[6] claims that if a father asks his son to wound him, the son is not bound by the prohibition of striking a parent. Some[7] raise a possibility that this enables a father to request his son to treat him even if unnecessary damage may occur. However, this suggestion is problematic on a few grounds. The Rivash[8] says that granting permission exempts someone from damage payments but does not permit bodily damage. Furthermore, it is unlikely that the parent does not mind if he suffers an unnecessary injury. His main intention, even if he says otherwise, is to permit a proper job, and the halacha is concerned that the son may botch the treatment. It is also quite clear that the early authorities did not accept the Minchat Chinuch’s approach.[9]
Ashkenazim can rely on the Rama’s ruling that if no one else can provide the treatment, then the child may. It is unlikely, though, that no one else is capable of performing routine injections. However, poskim discuss the parameters of “availability” in this context. Some suggest that the prospect that the child will do it for free, whereas others will charge, may be sufficient to render it a case of “no one else available.”[10] (This point is too complex and dependent on particulars to do justice to in this forum.) Sometimes, the chance of reliable treatment improves when the son provides the service himself.[11]
In sum, Sephardim should make every effort to find an alternative to a child injecting his parent.[12] For Ashkenazim, the main concern is to find the system that is best for the patient’s welfare. However, a child should avoid doing injections when comparable alternatives exist. One should consult a local rabbi in borderline cases.