Rabbi Eliyahu was acquainted with a certain rabbi who liked to check the suitability of shidduchim based on the couple's names. If their names didn't match according to his method, he would advise them to separate — even if they were already married. To say this brought about a lot of distress is a great understatement. As the Talmud relates, When a couple divorces, even the altar sheds tears.
Rabbi Eliyahu warned the rabbi how dangerous and problematic his method was, begging him to cease and desist, but the man paid no attention. Rabbi Eliyahu finally came up with a solution. He asked if he could check the names of the rabbi and his wife. When he made the calculations, he discovered that the couple — this rabbi and his wife — were completely unsuitable for one another. When Rabbi Eliyahu showed the rabbi his calculations, he told him he must divorce his wife because the numbers just didn't match up.
The rabbi was understandably shaken to the core. He clutched his head, crying, "How can I do that? I have eight children! How can I divorce my wife?"
Rabbi Eliyahu answered, "You don’t need to divorce her — but you can't continue to tell other couples to get divorced based on arbitrary, meaningless numbers and calculations." This time the rabbi listened.
Another time, an engaged couple approached Rabbi Eliyahu in tears. They had planned to marry, but their parents had sent them to a certain "rabbi" to have their names checked. He did so, announcing that they weren’t suited to one another. He advised them to break their engagement. The couple was completely distraught; they liked one another and truly believed they had found the right one.
Rabbi Eliyahu was terribly distressed and immediately summoned the rabbi and the parents of the bride and groom. Despite the other rabbi's discomfort, he refused to retract what he had said. So in the presence of the couple, the rabbi, and both sets of parents, Rabbi Eliyahu took the names of the young man and woman. Then he asked the girl's mother if her daughter had another name. She said that when her daughter was very young they had called her by a different name.
The rabbi who had forbidden the marriage meanwhile went pale. "Wait," he said, making calculations with pen and paper, "I didn't realize she had another name! If that's the case, then the formula is completely different and they can marry each other."