'Infirm' in the Bible

Who is infirm, and I am not infirm? who is stumbled, and I am not fired;

wherefore I am well pleased in infirmities, in damages, in necessities, in persecutions, in distresses -- for Christ; for whenever I am infirm, then I am powerful;

since a proof ye seek of the Christ speaking in me, who to you is not infirm, but is powerful in you,

for we rejoice when we may be infirm, and ye may be powerful; and this also we pray for -- your perfection!