Matthew 5:34

34Iἐγὼhoweverδὲsayλέγωto youὑμῖνnotμὴto swearὀμόσαιat allὅλως·neitherμήτεbyἐντῷheavenοὐρανῷ,becauseὅτι[the] throneθρόνοςit isἐστὶντοῦof Godθεοῦ·

But I say to you⁺ not to swear at all: neither by heaven, because it is the throne of God;