This passage is full of revelations, Samson was a product of prophecy, when the angel came the first time, manoah was not available, his wife told him everything the angel said, and he requested that he should repeat his visitation which the Lord granted, this shows to us that God is the God of second chance. What He did before He can do it again even in a greater dimension. And apart from that Manoah insisted on knowing the name of the angel, but the angel replied that he came on errand and the one that sent him is worthy of praise not him. The Lord cannot share His glory with any man.
We must remember that the manifest destiny of Sampson was to begin to deliver the children of Israel from the Philistines. Despite the failures in Sampson's life he did complete his manifest destiny. Thank God that he causes all things to work together for good to those who love the Lord and are called according to his purpose.
God gave me confirmation with this verse on may 23,2010 before i became with child...he told me i would bare a son and on my 17 week of pregnancy the doctor confirmed that prophesy