'Line' in the Bible

And the Lord said to him, Give him the name of Jezreel, for after a little time I will send punishment for the blood of Jezreel on the line of Jehu, and put an end to the kingdom of Israel.

Afterward the sons of Israel will return [in deep repentance] and seek the Lord their God and [seek from the line of] David their king [the King of kings—the Messiah]; and they will come trembling to the Lord and to His goodness and blessing in the last days.