Not only did hard work build character, it gave him a testimony to those around him. David was tending sheep for his father. Peter was a fisherman. Paul had a trade making tents. The Lord Himself was a carpenter by trade who was trained by Joseph.
Many young people go through college or Bible school and then on to seminary.
Upon graduation they seek a full-time ministry without the beneficial experience of having worked in the work place, been in the military or learned a trade. Then we wonder why they have problems in the ministry when faced with its rigid demands. Well, this can be one of the causes. Unless they worked their way through school, many do not really know what it is like to face the trials of the work place, nor have they developed the discipline of work. Furthermore, if, for whatever reason they must leave full-time ministry and work in a secular job, they have difficulty in supporting themselves and their families because they never learned a trade.