The Chronicler returns to Shelah in 1 Chronicles 4:21. This was the non-favoured line introduced briefly in 1 Chronicles 2:3 and ignored for the rest of the account of Judah. Shelah is the only surviving member of Juda’s family with Bathshua, his two brothers, Er and Onan both having died before producing offspring with Tamar (Genesis 38:1–30).
Judah forbade him to marry Tamar probably because he did not cherish the thought of losing his third son as well and in so doing violated the law of the levirate marriage. (If a man died, the next of kin was required to marry the widow of his older brother and so provide for him an heir who would receive the major portion of the inheritance and continue the family name. This form of marriage arrangement is known as levirate marriage. See Deuteronomy 25:5–10.) The right of the firstborn to inherit the headship of the family carried with it certain property rights and usually such titles as those of the high priesthood or kingship. Tamar the widow resorted to sin by deceiving her father-in-law to provide her the son that was hers by right.
Shelah’s first offspring is a boy named Er, which suggests the ultimate fulfillment by Judah of the levirate customs he had withheld from his eldest son Er (Genesis 38:9).
1 Chronicles 4:23 describes how descendants of Shelah lived...in the king's service.
This final section may be designed by the Chronicler to bolster the reputation of the Shelah clan by showing how Shelah fulfilled his responsibility to his brother and also how his descendants were supportive of the Davidic royal house.1 The Shelanites (descendants of Shelah) are described as those who were the potters who were inhabitants of Netaim and Gederah,
which may refer to place names. But an alternative translation is, These were potters, and those that dwelt among plants and hedges: there they dwelt with the king for his work
(1 Chronicles 4:23, KJV). This puts a different shade of meaning on the words. Spurgeon puts it this way: “All labour is honourable. No man ever needs to be ashamed of an honest calling. Whether a potter or a gardener, or whatever else his occupation may be, the workman need never be ashamed of his occupation by which he earns his honest wage. 'In the sweat of thy face shalt thou eat bread,' belongs to us all."2 They may have desired to live in the city, but they kept their appointed places, for they also were doing the king's work…. These potters and gardeners had royal company, for they dwelt 'with the king' and although among hedges and plants, they dwelt with the king there. No lawful place, or gracious occupation, however mean, can exclude us from communion with our divine Lord.
3 Whatever occupation we may find ourselves in, our King is there, because there is no work too menial for him.
The historian concludes this segment of the record by assuring his readers that he was in possession of ancient texts in composing it (1 Chronicles 4:22). This no doubt was to allay any suspicion that he depended only on unreliable oral tradition or even flawed copies of written documents. They were ancient, perhaps even viewed in a semi-canonical way.4
21 The sons of Shelah the son of Judah: Er the father of Lecah, Laadah the father of Mareshah, and the clans of the house of linen workers at Beth-ashbea;