Or HaChaim on Deuteronomy 18:13/אור החיים על דברים י״ח:י״ג

1 תמים תהיה עם ה׳ אלוקיך,"You shall be wholehearted with the Lord your G'd." Inasmuch as the previous verses dealt with people who engage in a variety of magic mixed with their religious tenets, the Torah has to emphasise that our relationship with G'd must be predicated on mutual exclusivity. The difference between Judaism and other religious beliefs is that those beliefs are based on a variety of terrifying phenomena in nature. As a result of the Gentiles' fears and traumas they resort to means which would foretell them what to expect and to try and take precautions against any disaster the stars foretell. We, who are convinced that G'd always has our best interests at heart, do not need to be terrified [except of our sinful conduct, Ed.]. You may therefore best translate this verse as meaning: "you will be complete i.e. תמים and at ease with the Lord your G'd provided תהיה עם השם אלוקיך, that you are on the same wavelength as the Lord your G'd. Any evil in store for you which you would find by consulting your horoscope is not bound to happen anyway. Our patriarch Abraham is the best example of this. He thought that because his horoscope told him that he would not have any children that G'd could not give him a meaningful reward; G'd taught him that he could overcome what he thought would happen (Shabbat 156). The word תהיה belongs both with the word תמים as well as with the words עם ה׳ אלוקיך. "You will be whole when you are on the side of your G'd."