Abdullah bin Masud relates Allah’s Messenger (peace and blessings of Allah be to him) as saying: Whom do you count as Raqub among you? They (his Companions) said: One who has no children (the children are born unto him but they do not survive). Thereupon he (the Holy Messenger) said: He is not a Raqub; Raqub is one who does not find his child as the forerunner (in the Paradise). He then said: Whom do you count as a wrestler among you? We said: He who wrestles with persons. He said: No, it is not he but one who controls himself when in a fit of rage.
(Sahih Muslim)
What the Blessed Messenger wanted to bring home to his Companions was that the words Raqub and Sura’ah carry deep spiritual meanings from the point of view of a person whose children do not survive in this life and thus he is sad because of the demise of his offspring. But in the domain of spirituality Raqub is one who does not face the pang of the bereavement of his children or does not show patience at such bereavement. There is no cause of sadness for a Raqub from the religious point of view as he is going to benefit by the demise of his child in the Hereafter, provided he shows patience at the death of his child or children.
The word wrestlerhas a deep spiritual meaning. He is one who has control over his anger and is able to counteract successfully the attacks of Satan.