Jamieson, Fausset and Brown on Jeremiah 3:14

14. I am married--literally, "I am Lord," that is, husband to you (so Jr 31:32; compare Ho 2:19, 20; Is 54:5). Gesenius, following the Septuagint version of Jr 31:32, and Paul's quotation of it (He 8:9), translates, "I have rejected you"; so the corresponding Arabic, and the idea of lordship, may pass into that of looking down upon, and so rejecting. But the Septuagint in this passage translates, "I will be Lord over you." And the "for" has much more force in English Version than in that of Gesenius. The Hebrew hardly admits the rendering though [Hengstenberg].

take you one of a city--Though but one or two Israelites were in a (foreign) city, they shall not be forgotten; all shall be restored (Am 9:9). So, in the spiritual Israel, God gathers one convert here, another there, into His Church; not the least one is lost (Mt 18:14; Ro 11:5; compare Jr 24:5-7).

family--a clan or tribe.