1 Chronicles 22:3
And David prepared iron in abundance for the nails for the doors of the gates, and for the joinings; and brass in abundance without weight; And David prepared iron in abundance for the nails for the doors of the gates, and for the joinings; and brass in abundance without weight;
David gathered iron and brass in great abundance as provision for building the temple for the Lord. The iron was intended for nails for the doors of the gates and for the joinings, while the brass was beyond weighing for its abundance. Although he made these large preparations, the Lord told him he was not the one to perform that building work.
That work was to fall to Solomon his son, the younger man who must do it. David's proper part was to advise, counsel, and encourage Solomon out of his own large experience. In this way God provides different sets of workmen for different stages of His cause. Older, weary minds that do not take in the greatness of the work and keep pace with its increasing demands should not block, hinder, or dictate how the younger workers whom God is qualifying to advance it should do their work.