Where is this notion contained in the Bible? It is not.
I am very disturbed by the number of people who are basically saying, "It has nothing to do with Christianity. It's 'Old Testament'." People who make these arguments are implying that God was wrong to give Samson the power to destroy those Philistines. You can't excuse it by saying, "Well, that was the Old Testament god", as if there is a different one in the 'New Testament'. This is exactly why I do not use the terms old or new testament. Far too many so-called Christians ignorantly dismiss the Hebrew/Aramaic scriptures.
Samson did not commit a sin by bringing down the temple. He gave his life to destroy the pagan oppressors of God's people. These were not innocents he specifically targetted. The Philistines he killed (with God's help) had attacked him, blinded him, enslaved him and held him captive. He killed his captors, he never went after "innocent" people in the entire time he judged.
I did not say that suicide was mentioned in the bible, it may or may not be, however, I did say the Christian religion forbids it and considers it a sin. This is a true statement. Sorry for taking so long in getting back on this post.