Answer: In the previous Halachot we have discussed the basis for washing one’s hands in the morning. We have also mentioned in passing that one should preferably not touch any food items before washing one’s hands, for an evil spirit rests on one’s hands prior to washing them.
Based on this it would seem that one should take care to wash the hands of young children, including infants, for we must assume that they will touch food items while this evil spirit still rests on their hands. The Peri Megadim (Mishbetzot Zahav, Subsection 7) mentions this and writes that he does not know why people are not careful about this, however, it is correct to wash their hands every morning, for the issue of the danger posed by this evil spirit is more severe than an issue related to a prohibition. Maran Ha’Chida in his Moreh Be’Etzba writes likewise. Hagaon Ya’abetz writes in his Siddur that people are customarily not so meticulous about this matter, however, halachically, one should take care to wash one’s children’s hands in the morning.
Hagaon Harav Eliezer Papo (author of Peleh Yo’etz and father-in-law of Hagaon Harav Aharon Azriel, who was one of Jerusalem’s greatest luminaries) writes in his Chesed La’Alafim: “How good and worthy it is to wash the hands of one’s infants so that they may grow up amid purity and holiness.” We can infer from his words that this is not obligatory according to the letter of the law; rather, it is only a gesture of cleanliness and purity. Several Poskim write likewise that this is not mandatory according to the letter of the law, for the evil spirit does not rest on the hands of children. Hagaon Rabbeinu Zalman explains this further in his Shulchan Aruch that the primary entry of the holy soul into a human being occurs when he becomes obligated in Mitzvot, i.e. the age of thirteen for a boy and the age of twelve for a girl. Conversely, the power of impurity does not become strong within a person until he has the power of holiness within him. Nevertheless, the words of Hagaon Harav Eliezer Papo still apply, that as a result of washing the child’s hands, the child will grow with an added measure of purity, even if the evil spirit that rests upon the child’s hands is not yet at its fullest intensity.
Thus, halachically speaking, it is certainly worthy and proper to follow the opinion of the Poskim who write that one should wash one’s children’s hands in the morning, especially at a stage when they already touch food. By doing so, the child will grow up amid purity. This is indeed the prevalent custom today among many G-d-fearing people.