When you have gotten a fruitful possession through all the field, sow it with your own seed, trusting in the goodness of your stock.
KJV
Sirach 26:20
When thou hast gotten a fruitful possession through all the field, sow it with thine own seed, trusting in the goodness of thy stock.
Parallel Translations
My sonne, kepe the strength of thine age stable, and giue not thy strength to strangers.