Mahli
Mahli is the name of two Levites, both standing in the line of Merari. The older Mahli is one of the two sons born to Merari himself; the younger Mahli is a grandson, son of Merari's other son Mushi. The Hebrew Bible keeps the two carefully distinguished by naming the father each time, so that the clan name "Mahlites" can attach to either branch without confusion.
Mahli the Son of Merari
The first Mahli appears at the head of one of the two Merarite houses. Levi's three sons are listed as Gershon, Kohath, and Merari (Gen 46:11; Ex 6:16; Nu 3:17; 1Ch 6:1), and Merari in turn has two sons, Mahli and Mushi: "And the sons of Merari: Mahli and Mushi. These are the families of the Levites according to their generations" (Ex 6:19). The Chronicler repeats the same pairing — "The sons of Merari: Mahli and Mushi. And these are the families of the Levites according to their fathers' [houses]" (1Ch 6:19) — fixing Mahli as one of the two ancestral heads from whom the Merarite Levites descend.
The wider Merarite house attached to this Mahli is the one charged in the wilderness with the heavy structural work of the tabernacle. Its prince was Zuriel, who camped on the north side (Nu 3:35), and its appointed service was "the boards of the tabernacle, and its bars, and its pillars, and its sockets, and all its instruments, and its [the tabernacle's] service" (Nu 3:36; cf. Nu 4:29, 42). Because their burden was timber and sockets rather than the lighter sanctuary furniture, Moses gave the sons of Merari "four wagons and eight oxen ... according to their service, under the hand of Ithamar the son of Aaron the priest" (Nu 7:8). Mahli the son of Merari is the head of one half of that working force.
His name surfaces again, several centuries later, in the return from exile. When Ezra is gathering Levites to accompany him from Babylon, the list reads: "And according to the good hand of our God on us they brought us a man of discretion, of the sons of Mahli, the son of Levi, the son of Israel; and Sherebiah, with his sons and his brothers, eighteen" (Ezr 8:18). The shorthand "the son of Levi" passes over Merari and runs the descent straight back to the patriarch, but the "sons of Mahli" here are the post-exilic representatives of the elder Mahlite branch.
Mahli the Son of Mushi
The second Mahli stands one generation lower. He is the son of Mushi, who is himself Merari's other son, so that this Mahli is nephew to the elder Mahli and bears the same name. The Chronicler's Levitical roster for the reorganization under David lists him plainly: "The sons of Mushi: Mahli, and Eder, and Jeremoth, three" (1Ch 23:23). The list is repeated, with a spelling variant for the third brother, in the parallel record of priestly and Levitical courses: "And the sons of Mushi: Mahli, and Eder, and Jerimoth. These were the sons of the Levites after their fathers' houses" (1Ch 24:30).
The same Mahli also appears, much earlier in the Chronicler's genealogy, in the ancestral line of the singer Ethan. Tracing Ethan's descent upward through the Merarite branch on the left of the sanctuary, the list ends: "the son of Mahli, the son of Mushi, the son of Merari, the son of Levi" (1Ch 6:47). The order of the names confirms the placement — Mahli here is named as Mushi's son, not as Merari's son — and so links the younger Mahli to the singers appointed for the house of Yahweh.
The Two Lines Together
Read together, the two Mahlis show the way the Merarite house propagated. Merari's two sons, Mahli and Mushi, head the two original sub-houses (Ex 6:19; 1Ch 6:19); within Mushi's sub-house, the name Mahli is then given again to a grandson (1Ch 6:47; 23:23; 24:30); and centuries later the elder Mahli is still recognizable as the ancestor of a returning exilic family (Ezr 8:18). What the genealogies preserve, in other words, is not one man but a Levitical name carried forward through the Merarite line from the wilderness tabernacle to the post-exilic temple service.