Psalms 112:2

His seed shall be mighty upon earth - His children; his posterity. That is, they shall be prospered; honored; distinguished among people: distinguished for their virtues, for their influence, for their success in life. This refers to what was regarded among the Hebrews as an object of great desire, and is in accordance with the promises everywhere found in their Scriptures. See Psalms 25:13, note; Psalms 37:25, notes. Compare Genesis 12:2; Genesis 17:6; Exodus 20:6. It is in accordance, also, with a general fact in the course of events. The best security for the virtue and success of children is the virtue and the piety of parents; the surest inheritance as pertaining to happiness, respectability, and usefulness in life, is that which is derived from the example, the prayers, the counsel of a pious father and mother.

The generation of the upright shall be blessed - The family; the children. Such promises are to be expected to be fulfilled in general; it is not required by any proper rules of interpreting language that this should be universally and always true.