The chapter builds a small procedure out of one family metaphor. The world had a beginning which may be taken as the mother of the world. Having got the mother, one knows the children. Knowing the children and going back to hold to the mother, one is in no danger to the end of life.
The sequence has three steps and the third is the one that is usually dropped in summary. Reach the source. From the source, understand what comes from it. Then return to the source, still holding what you learned about the children. It is not a movement away from the world of particulars and it is not a permanent residence at the origin; it is a circuit, and the chapter measures its success in a very ordinary currency, that of not coming to harm before you die.
The mother image is the book's standing figure for the source, used in chapter one where the named is called the mother of the ten thousand things, in chapter twenty-five where the thing born before heaven and earth might be the mother of all under heaven, and in chapter twenty where the isolated speaker says he values being fed by the mother.
What distinguishes this chapter is the pairing with children. Elsewhere the mother has no offspring named; here the derived things are given a term of their own, and the relation between origin and particulars becomes a relation a person can move along in both directions. That two-way movement is what the chapter recommends, and it is why the passage reads as practical where the other mother passages read as cosmological.