What is the ruling on wiping the sides of the head during ablution (Wudu’)? Is it true that Ibn Umar wiped part of his head? And what is the method for wiping the entire head once in Wudu’, following the example of the Prophet (peace be upon him)?

Wiping the entire head is a matter of dispute, and the most preferred and cautious opinion is to wipe the entire head. Wiping the head by moving the hands forward and backward is a recommended Sunnah. It has been authentically reported from Ibn Umar that he sufficed with wiping only part of his head, and there is no authentic report that any of the Companions objected to that. As for the manner of the Prophet's (peace be upon him) wiping, he used to wipe his head with both hands, moving them back and forth, starting from the front of his head then to his nape, then returning them to the place where he began.