Egg On

OED

Egg, 2. Fig. That which contains the germ of anything; generally in a bad sense. Also in phrase, To crush in the egg.

Egg, v., 1. trans. To incite, encourage, urge on; to provoke, tempt.

1566 Drant. HoraceÕ Satires V. D b. Ile egge them on to speake some thyng, whiche spoken may repent them.