—Allah will make room for you.
As for making someone stand up and then sitting in his place, that is impermissible—even in the prayer rows. If you see a person in the first row, it is not lawful for you to say to him, “Get up,” and then occupy his spot; even if he is a boy, once he is praying it is not permissible to remove him from his place and pray there yourself. The hadith is general, and the child is required to pray with the congregation and remain where he is.
Regarding the Prophet’s ﷺ statement, “Let those of you who are mature and prudent stand nearest to me,” this is a directive to the sane, responsible adults to come forward so that they are directly behind the Messenger ﷺ. It is not a prohibition on youngsters being near him; had that been intended he would have said, “No one should stand close to me except those who are mature and prudent.” Rather, by instructing the mature and prudent to be next to him, he was urging them to advance so that they would be right behind the Prophet ﷺ, hearing his words, learning his law, and conveying it to the people.
ʿAbdullāh ibn ʿUmar (may Allah be pleased with them both), out of his scrupulous piety, would not sit in a place from which someone had risen and said, “Sit in my spot.” He feared that the person had stood up only out of shyness and embarrassment before Ibn ʿUmar. And it is well known that whoever is offered a gift