Avrohom tells the Malachim that Sara his wife is in the tent. Her modesty stands as an example for women and even Dovid Hamelech would credit his royalty to this virtue. Yet the Midrash tells us that Yael who ‘went out of her tent’ was superior in greatness.

Sources:

Parshas Vayera Perek 18 Possuk 9

Rashi on the Possuk

Gemara Maseches Yevamos 76 B

Shoftim Perek 4 Possuk 18

Commentery of Megalle Amukos on the Possuk

Midrash Rabba Vayera Parsha 48 Perek 15