When her sister Leah, who was also married to Jacob, had four children and she, herself had none, Rachel gave her handmaiden Bilhah to Jacob to bear children on her behalf. The first son born thus was Dan.
And she became pregnant and bore him a son. Then Rachel said, "God has vindicated me; he has listened to my plea and given me a son." Because of this she named him Dan. (Genesis 30:5-7)
Dan does not figure much in the Bible until he received his father's blessing.
"Dan will provide justice for his people
as one of the tribes of Israel.
Dan will be a serpent by the roadside,
a viper along the path,
that bites the horse's heels
so that its rider tumbles backward.
Part of the prophecy was perhaps fulfilled by the judgeship of Samson, who was of the tribe of Dan. The tribe of Dan had their place in the march through the wilderness on the north side of the Tabernacle. It was the last of the tribes to receive a portion in the Land of Promise.
The territory of Dan extended from the west of that of Ephraim and Benjamin to the sea. It was a small territory, but was very fertile. It included in it, among others, the cities of Lydda, Ekron, and Joppa, which formed its northern boundary. But this district was too limited. Being pressed by the Amorites and the Philistines, whom they were unable to conquer, they longed for a wider space. They accordingly sent out five spies from two of their towns, who went north to the sources of the Jordan, and brought back a favourable report regarding that region. "Arise," they said, "be not slothful to go, and to possess the land," for it is "a place where there is no want of any thing that is in the earth". On receiving this report, 600 Danites girded on their weapons of war, and taking with them their wives and their children, marched to the foot of Hermon, and fought against Leshem, and took it from the Sidonians, and dwelt therein, and changed the name of the conquered town to Dan.