Rashi on Deuteronomy 7:13/רש"י על דברים ז׳:י״ג

1שגר אלפיך means the offspring of thy oxen which the female casts out (שגר) from its womb.

2ועשתרות צאנך AND THE BREEDS OF THY FLOCK — Menachem ben Seruk explains this expression to be parallel to אבירי בשן, which means: "the strong rams of Bashan” (Psalms 22:13), i.e. the choicest of the sheep, similar to (Genesis 14:5), “Ashteroth (עשתרות) Karnaim", where also it is an expression for “strength" (so that עשתרות denotes “the strong ones"). Onkelos. however, translates it: “and the flocks of thy sheep". Our Rabbis said: Why is their name called עשתרות? Because they enrich (עשר) their owner (through the sale of their wool, etc.) (cf. Chullin 84b).