When i am weak..

But He said to me, “My grace is sufficient for you, for My power is perfected in weakness.” Therefore I will boast all the more gladly in my weaknesses, so that the power of Christ may rest on me. (2 Cor 12:9)

Therefore I take pleasure - Since so many benefits result from trials; since my afflictions are the occasion of obtaining the favor of Christ in such a notable  degree, I rejoice in the privilege of suffering. There is often real pleasure in affliction, self-contradictory as it may appear. Some of the happiest persons are those that have been deeply afflicted; some of the purest joys which I have witnessed have been manifested in the hardest times.

For when I am weak, then am I strong - When I feel weak; when I am subjected to trial, and nature faints and fails, then strength is imparted to me, and I am enabled to bear all. The more I am borne down with trials, the more do I feel my need of divine assistance, and the more do I feel the benefits of divine grace.

Therefore I take pleasure in infirmities, in reproaches, in necessities, in persecutions, in distresses for Christ's sake: for when I am weak, then am I strong. (2 Cor 12:10)

Such was the promise in Deuteronomy 33:25; "As thy days, so shall thy strength be." So in Hebrews 11:24; "Who out of weakness were made strong." What Christian has not experienced this, and been able to say that when he felt himself weak and felt like sinking under the accumulation of many trials, he has found his strength according to his day, and felt an arm of power supporting him? It is then that the Redeemer manifests himself in a special manner; and then that the excellency of the power of Christ is truly seen and its power appreciated and felt.

So, I find joy in weaknesses, not just for their own sake, but because they allow me to experience the grace of God and receive greater comfort. These difficulties, including external hardships and anything that is considered lowly or distressing, be it from Satan or the world, serve to highlight the grace, power, and strength of Christ, making his greatness more apparent. In this context, "infirmities" is a broad term that encompasses all forms of troubles and afflictions.It seems to be a general term, which includes and is explained by the following particulars:

• In reproaches; of Satan, the accuser of the brethren, who sometimes reproachfully endeavour to take away their characters, credit, and reputation; the faithful servants of Christ must go through bad report, and suffer shame for the name of Christ; but these reproaches with Moses are esteemed by them greater riches than the treasures of Egypt:
• In necessities; not of the soul, the better part, there being a sufficiency of grace in Christ to relieve all its wants; but of the body, the apostle was sometimes reduced to very necessitous circumstances, wanting the common necessaries of life, being hungry, thirsty, and naked, and yet cheerful:
• In persecutions; from place to place by the enemies of the Gospel, by whom he was severely handled by beating, scourging, and imprisonment; but his stripes were the marks of the Lord Jesus; his chains were his crown, and his prison a palace to him:
• In distresses, or "straits"; both as to body and mind, encompassed with such difficulties that he knew not what way to take, or course to steer: and all
• For Christ's sake; not for any real crime done by him, but for a profession of Christ, preaching his Gospel, and for the glory of his name; and which made all these afflictions so delightful to him, having in the midst of them the love of God to comfort him, the power and strength of Christ to support him, and the grace of the Spirit to assist him, and the presence of all the three Persons with him; this he suggests to be the ground and reason of his delight and pleasure, in such otherwise disagreeable circumstances:

For when I am weak, then am I strong; when he was attended with all the above mentioned infirmities, when laden with reproaches, surrounded with necessities, followed with persecutions, and brought into the utmost straits and difficulties, and was most sensible of his weakness in himself to bear and go through all these things; then was he upheld by the divine arm, and strengthened by the power of Christ; so that he was not only able to sustain the conflict, but became more than a conqueror, and even to triumph in the midst of these adversities; 

He could and did readily take the advice in Joel 3:10, and express himself in the same language there directed to, and to which he seems to refer, "let the weak say I am strong"; for he that is weak in himself, and sees himself to be so, is strong in Christ, and has a comfortable experience of renewed strength from him, as his day is.

The Jews have a saying  somewhat like this, "the righteous even , "when they are weak strengthen themselves"; as it is said, Genesis 48:2, and the wicked, though in their strength, fall, according to Esther 7:8.''

When Jacob was told, 'Your son Joseph has come to you,' Israel rallied his strength and sat up on the bed. (Gen 48:2)