Thomas, which is called Didymus - These names express the same thing. One is Hebrew and the other Greek. The name means a twin.
Die with him - It has been much doubted by critics whether the word him refers to Lazarus or to Jesus. They who refer it to Lazarus suppose this to be the meaning: “Let us go and die, for what have we to hope for if Jesus returns into Judea? Lately they attempted to stone him, and now they will put him to death, and we also, like Lazarus, shall be dead.” This expression, is supposed to be added by John to show the slowness with which Thomas believed, and his readiness to doubt without the fullest evidence. See John 20:25. Others suppose, probably more correctly, that it refers to Jesus: “He is about to throw himself into danger. The Jews lately sought his life, and will again. They will put him to death. But let us not forsake him. Let us attend him and die with him.” It may be remarked that this, not less than the other mode of interpretation, expresses the doubts of Thomas about the miracle which Jesus was about to work.