Charles H. Spurgeon on Psalms 107:18

They draw near unto the gates of death. Death is a great commander, a great tyrant, and hath gates to sit in, as judges and magistrates used to `sit in the gates.' There are three things implied in this phrase.

1. First, "They draw near unto the gates of death", that is, they were "near to death"; as he that draws near the gates of a city is near the city, because the gates enter into the city.

2. Secondly, gates are applied to death for authority. They were almost in death's jurisdiction. Death is a great tyrant. He rules over all the men in the world, over kings and potentates, and over mean men; and the greatest men fear death most. He is "the king of fears", as Job calls him, Job 18:14; aye, and the fear of kings ...Therefore it is called "the gate of death." It rules and overrules all mankind. Therefore it is said "to reign", Ro 5:21. Death and sin came in together. Sin was the gate that let in death, and ever since death reigned, and will, till Christ perfectly triumph over it, who is the King of that lord and commander, and hath "the key of hell and death", Re 1:18. To wicked men, I say, he is a tyrant, and hath a gate; and when they go through the "gate of death", they go to a worse, to a lower place, to hell. It is the trap door to hell.

3. Thirdly. By the "gate of death", is meant not only the authority, but the power of death; as in the gospel, "The gates of hell shall not prevail against it", Mt 16:18; that is, the power and strength of hell. So here it implies the strength of death, which is very great, for it subdues all. It is the executioner of God's justice. —Richard Sibbes.