What signs were sent by Zeus as omens signaling to Odysseus before test of the bow that his attach upone the suitors would succeed?

In Book 20 Odysseus prays to Zeus, asking for two omens, one from the mouth of someone in the house and one from the outside world. Zeus responds with a clap of thunder even though the day is sunny. One of the women outside grinding wheat hears the thunder and says she hopes it is a sign from Zeus that the day is the last one she will have to grind wheat to prepare bread for the suitors. When he hears her comment, Odysseus is assured that Zeus has answered his prayer.