In France, a girl started having seizures. During her seizures, she repeated prayers in German language. The girl was French and did not know German language. Physicians started saying, “This girl does not know German language but she is speaking German, therefore, it has been proved that she is possessed by a ghost.”
A medical practitioner became interested in the matter. He was a renowned expert on memory. When he started searching, he found that her mother used to work for a German priest when the girl was two or two and a half years old. The girl used to be in a cradle while the priest was delivering the sermon in German. After finding this out, the doctor set out to find the German priest. He came to know that the German priest was in Spain at that time. On arriving in Spain, he found that the priest had retired and had gone to Germany. He went to Germany in his search. On arriving there, he found that the priest had died. He did not abandon his effort. He asked his family to show him the old papers of the priest if they had any. The family searched the house and found some papers. They gave the papers to the physician. He looked at the papers and discovered that they were the sermons of the priest and they contained the same prayers that girl verbalized when she had a seizure.
Note that the few things the priest uttered in the presence of the girl when she was only a couple of years old were saved in her brain by Allah, the Almighty.
This is the reason that the Holy Prophet, may peace and blessings of Allah be upon him, has directed that when a child is born in the house of a Muslim, immediately recite the call for Prayer in one ear of the child and the call for the start of the Prayer in the other ear of the child.
European scholars have found now that old things stay saved in human brain for many years, while Muhammad, the prophet of Allah, may peace and blessings of Allah be upon him, pointed to this fact fourteen hundred years ago.