Zeus, the king of the gods, often gave his approval for battles through thunder and lightning. In Homer's "The Odyssey," when Odysseus battles the suitors, a deafening clap of thunder is heard after he shoots the first arrow, indicating Zeus' approval.
Apollo's Light
Apollo, the god of light, often sent bright, encouraging rays to signal his support. In "The Odyssey," when Odysseus strings the bow, sunlight pierces through the clouds and illuminates the hall momentarily.
Athena's Presence
Athena, the goddess of wisdom and warfare, frequently appeared in person to lend her support in battles. In "The Odyssey," Athena disguises herself as Mentor, Odysseus' old friend, and guides Odysseus and Telemachus during their plan to defeat the suitors.
Divine Assistance
The gods could also offer tangible assistance in battles. For instance, Athena intervenes directly by pushing up the bow and making Odysseus invincible to harm during his fight against the suitors.
Omens and Prophecies
The gods could convey their approval through omens or prophecies. In "The Odyssey," the seer Theoclymenus predicts the downfall of the suitors, foreshadowing Odysseus' victory.