A common Quarian phrase, from the video game trilogy Mass Effect, meaning "By the home world I hope to see one day." Exiled from their homeworld, the Quarians (an alien race known for their technological genius) have lived as space-nomads for about three centuries. Like the phrase "peace be with you", the phrase "keelah se'lai" can mean many things. But whether to express surprise, happiness, or frustration - for them to swear on their homeworld is the meaningful expression they have.
to an army waiting to massacre a synthetic race that drove them from their homeworld, although, ha-ha-ha, they claim to be peaceful now, a frustrated soldier says: "The enemy doesn't want to fight you! If you can believe that for just one minute, this war will be over. You have a choice. Please. Keelah Se'lai."